The first step to making an airsoft team is to find good people. So, you have airsoft wars with your friends. You then pick out some really good players you notice. Once you do pick the players, practice for any competition that comes up. When that competition happens, your team will play pretty decent. Now don't blame me if you don't win but it will get yourself pretty far. (If you get good people that is.) If you notice that someone is good in one category, put them to work at it in an airsoft war. Also, I don't know why the picture is small.
Step 1: Practicing
Now I'm not just posting this to tell you to get good people. You need to practice, practice, practice, and......practice. I would do about 1 a week or so. You just need to see that your team is improving. If not, practice more. (I doubt that would happen.) But just saying. If their is a certain member that needs to improve, put your main focus on him/her :P and try to give him/her tips on how to improve or they can also practice more if it comes down to the decision.
Step 2: Gear
Now this might be the most important section. Your team needs GOOD gear. For example an M4, even better. You also need a good supply of grenades. My friend was once at an airsoft competition and a guy hoked up a car battery to a minigun. (Don't ask) They guy kept pelting them everywhere they went. He was going for a reload when my friend threw a tornado airsoft grenade in the shack he was in. They creamed him. That's only one good reason why grenades rock. Back to the guns. You will want some pretty heavy duty guns for heavy duty things. So when you are in an airsoft competition, you will beat them so bad they're gonna go home crying. You seriously have to get good guns. As for the mines and cannons,those work too. I would set up a couple mines around your flag and make sure that they don't see them. (Just make sure you don't step on on.) The cannons you should put in a place where the enemy does not expect it to be there. For example, on their face. No, no, no, no. Just kidding. Probably in a short tree or a bush.
Step 3: Protection
I guess this would fall into the gear section but, I want to have a slot where I can tell more about it. Now in an airsoft war you don't want to dress up like Ronald McDonald and get pelted like crazy. Ya gotta get good armor in order to not get hurt I mean this so take my word, you don't want to go an an airsoft field without any armor. That would hurt. A lot. Now, if you play a sport like football or soccer, wear your gear and shin gaurds because it is a lot better than having to go to the store and buy some. The halo guys below, that is a different situation because they are wearing armor except like a halo dude does. If ya wear armor. Ya don't get hurt. So make sure that your team has most of all the armor and you're good.
Step 4: Now go win an airsoft war!
With your team ready you can dominate. Now have fun!