Learn to trust before you have a threesome. When you realize that a threesome is more complicated than a normal two-person relationship, you need to trust your partners. You don't want your dreams to go up in smoke before you start enjoying your threesome. Trust is the key to a good relationship since you will never know what will happen and you have to make sure you all will work together. To maintain the swinger lifestyle go as you expect, you have to trust each other, instead of distrusting each other. Whether you have been in threesome before or not, you need to learn how to trust other people in advance.
Being single, your partner will usually be a couple, so you must learn to be independent when you are separated from them. Couples will only stay close when they have a threesome with you, because they tend to be more conservative. They may even introduce you to their family, friends, or even colleagues or classmates because they want it to remain a secret. The result is that after you've had a three-way hookup, you'll still be on your own, just like before. If you try to rely more on your partners, you'll scare them off, and of course your relationship with them will break down. So, learn to be independent, couples will be happy to be with you, and you will usually have a very good chance of going well.
Once you've established a relationship with a couple, feel free to unleash your sexuality, because they need you to. More often than not, couples are willing to take a risk with a threesome simply because they need something exciting and adventurous to get them back on their feet. If you can't get yourself up to speed, you won't be able to grab their heart any time soon. Remember, you're here for fun and excitement, too, which is why you hit it off. You don't have any need to feel the slightest bit awkward, even if you don't have any prior experience with it. You will do better and better, as long as you keep an open mind, and at the same time couples will help you a lot.