Cock and ball bondage is often associated with cock and ball torture, but it's actually useful outside of CBT play as well. Simply put, it makes everything more sensitive. Quite a few tops will start most any session with a little cock and ball bondage. I like to do so myself; I'm particularly fond of ball bondage. It might be a little bit of work at first, but if you do it frequently it gets much easier, to the point where you can have a nicely tied up package in less than 30 seconds if you so desire. Also, as you gain confidence, you can have fun binding your pet's cock and balls in different ways or with different materials.
First of all, having a sub with shaved pubic hair always helps. Not only can you see what you're doing, but your pet's hair won't get stuck in your rope work. There's no good excuse for your sub not to shave or at least trim his pubic hair. If he doesn't agree, and you can't persuade him, don't go through the hassle of trying to avoid the hair when you tie and if you catch a few you can bet he will quickly change his mind. Smaller ropes can cut further into your sub, but are generally easier to tie than thicker ropes. A shoelace or paracord is as small as I would recommend for safety, and is also great for beginners because of how easily you can tie them. You can usually find them for cheap at a dollar store or Walmart, but using shoe laces from an old pair of shoes usually works just as well; your pet may even find this more exciting if he has a foot fetish. If you want to play with a rougher material, or just like the appearance of larger ropes, you can find them at most any home improvement store. I suggest staying at or under a quarter inch rope to make sure you can still easily tie it. If you really want to go large, if a thicker rope looks like more fun, then go for it. The effect is always about the same, so the most important part is having fun. And there's no need to limit yourself to rope. Rubber bands and other elastic ties such as hair ties work well as they have enough give to allow blood through even when doubled or tripled over. There's no limit to what you can use. If you're only interested in it for the effects, then use what works the fastest for you.
You can bind either the cock, the balls, or both the cock and balls at once. The easiest thing to do is to bind the cock and balls together. You can just circle around everything and tie them up with a nice bow just like you would your shoes. I prefer to bind the balls separately from the cock. Tugging on the balls is so much more fun and effective when it doesn't pull the cock along with them. I've done this for some ball pulling fun during sex. However binding just the balls can be tricky as they are quick to slip away. It's even more tricky if you want to bind each one separately. If you want to accomplish this and are new to such play, or just prefer an easier approach, I suggest you start with one tight binding around both the cock and balls, and then work on securing just the balls. It's easier to tie them up when they can't easily get away. Once that's done you can undo the first binding around the cock and balls, and retie the cock separately if desired. Don't worry about not getting it right the first or second time, or the tenth time. As you work with the rope, binding the cock and balls, you are also providing your pet with some stimulation, he will most likely enjoy you experimenting and playing around with bondage. It's less stressful for you and your sub if you think of it as "playing around" when you're having trouble getting something to work.
Binding the cock at the base causes blood to flow out slower without hindering the inflow to the same degree, thus making it harder, fuller, and more erect. And needless to say, this is more fun for everyone. Skin that must be more flexible and elastic in an area will feel softer when bunched up, but it is also less sensitive. The cock is one such area, and thus, a more erect cock will feel more of your touch. As it becomes more engorged, the skin stretches out. This not only causes more nerve endings to be reachable, but presents more surface area that can be stimulated. There's also quite a noticeable mental effect on a man when his cock is so fully engorged. It's more than just a subconscious increase in how horny he is. Finding oneself so hard really builds anticipation. When so fully engorged, there's something palpable about his cravings, his desperation; something I can only describe as carnal.
Similarly, binding the balls not only traps the balls, but stretches the ball sack (scrotum). The scrotum can contract when cold, during exertion, and even when sexually excited; all of which can occur while playing with your sub. This contraction "thickens" the skin by causing lots of tiny wrinkles which in turn hide many nerve endings. (Technically, this is caused by the dartos fascia.) When you tie up a sub's balls you are also loosening up the skin of the scrotum and exposing all of those hidden nerve endings. A stretched scrotum can even be so sensitive as to be ticklish for some men. If you intend to try this, you may get better results with a less horny sub. Blindfolds tend to increase ticklishness as well. Perhaps make an experiment out of it, try it out before and after orgasm.
Normally, if you were to slap your sub's balls, the impact would cause them to move, maybe even swing away. Most of the energy is converted into motion and then slowly absorbed (relatively speaking) by soft tissues on the side opposite your impact. However, when balls are tied up, they have nowhere to go upon impact. They are trapped against the bindings themselves. While you're still likely to see some movement, the balls now feel most of the energy from the impact. The end result being that bound balls are more sensitive. Likewise, balls bound separately will be even more sensitive than those bound together since they can't transfer force between each other. And I should mention this loss of energy happens even with normal fondling of the balls. They move around as you touch them, so it's not only high speed impacts that become more intense. All of this combined means bound balls are more sensitive in every way, even to light touching. Ball binding is often used with CBT because it takes less effort to cause an equal amount of pain. Less force means less chance of an injury. If you start kicking or striking them at full strength then there is bound to be an increased chance of certain injuries, but as long as they are firmly bound in place and not free to swing around, it will still reduce the chance of the much more common testicular torsion injury that can occur during those higher risk activities. Testicular torsion is probably the most common injury from kicking, and also the injury most likely to require surgery or result in the loss of a testicle.
One thing everyone worries about is, how long can you go? As a general rule, just rebind your pet every 20 to 30 minutes or so to keep things circulating. As long as you make sure you can fit a finger between the genitals and the bondage you can easily stretch that to an hour. I try not to go longer than that since I can lose track of time at that point. Sometimes, and only with certain people, you will notice a color change, but it's nothing to be worried about. Color changes or lack thereof do not indicate an urgency, or the lack of urgency. Color change is an acceptable side effect of increased blood pressure in an area. Some men's cocks will even change color just from an erection. What you should really be watching out for is a drop in temperature and swelling. If the area feels cold, then the blood flow that usually keeps the body warm has been hindered long enough for the area to lose its warmth. This in itself isn't a problem, however the cold will usually coincide with numbness and a loss of sensation, which is the opposite of what we want. Sure, it might let him take more, but that's cheating! And anyway, why put more work into it then you have to? Don't let him go numb. The other thing I mentioned was swelling. Watch for the swelling of the soft tissue of the cock or the scrotum. You can check for it below and around a binding. The swelling doesn't mean some horrible damage has been done, and it should go down once circulation returns. But it does mean you should immediately get circulation back to the area to prevent damage, and it's probably a good idea to leave the area unbound for a bit. If this does happen, the next time you bind the area keep a close eye out, if you see any signs of swelling try a looser tie.
There are good reasons for cock and ball bondage even if you aren't interested in CBT. Binding your sub's cock and balls can also make an otherwise less fulfilling orgasm more intense. I hate to literally sound lazy, but this is a good thing to learn if you want to give your pet more satisfaction with less work. From a selfish point of view, this increased sensitivity not only makes things easier for you, but it makes them more fun for you as well. Once bound, you will find you get better results for the same amount of effort and who doesn't love a better reaction? A harder, more erect, and more sensitive sub will reach his tipping, or breaking point quicker. And I think everyone can agree, submissives are more fun to play with when they're more desperate. It may take a little time to get comfortable with cock and ball bondage, but in the end, the payoff is worth it for everyone involved.