1. Be Confident
You don't want to be cocky, or take all the thunder, but your buddy will feed off of your appearance and energy. If you're feeling confident, he will too, and you will be much more likely to help him out.
2. Compliment Him, But Subtly
It's easy to be very obvious that you're trying to set your friend up, and that is a turn-off. At the same time, you want to boost your friend up. It's a fine line, but just sneak in a few positive qualities about your friend every now and then. Easy.
3. Know When To Leave Him Alone
At some point, your friend is going to have to take over for himself. When it comes time for this, you can't be sticking around. Again, be subtle, but slowly remove yourself from the situation. They'll take the hint.
4. Always Have Your Phone On You
The best wingman is always available. That's why our phone number has a 24/7 hotline. You never know when your friend may need you. It could be advice, it could be help with homework, or even cooking. Regardless, you need to be there for when the time calls.
5. Know When He Needs Help
The best wingman will eventually have to do what their friend does not want. They may be angry in the moment, but that does not mean it is the wrong decision. Use good judgement, and if you think your friend needs to be removed from the situation, be that guy.