I play at a professional field and get in about a dozen 15 minute games a day. Mostly walkons and a few regulars. Up to 40 people on a team and most are newbies, I try to:
Organize. Knowing the fields, I outline a general lay of the land and what our primary objectives are. Usually a left, middle, and right breakdown. Get the people to decide which direction they want to go at the break and have them move to that side of the start point so they are not running through each other. Make sure the groups are relatively equal in size and ability if possible.
Safeties off barrel plugs out. Test fire ONE shot to be sure markers are working as most are rentals. NO ONE stays back to "guard " the flag. All guns up to the front giving our team more firepower and more angles to shoot from. Also for a newb it is no fun to sit in the back and never see any action and never learn how to play. back sitting assumes your own team is going to be wiped out and you, all by yourself, will hold off the enemy.
On the break SPRINT as far as you can and grab as much real estate as possible. Move until you observe the other team or you have gone halfway across the field. This does two things, You will observe the enemy moving into position and you can call their locations out to your teammates, and it gives you more room if you have to adjust your plan( but that never happens, right?)
Communicate. The other team knows you are here. Forget stealth, don't worry about stepping on sticks or dry grass or paint balls rattling in your pods( that always makes me laugh). With 2 dozen guys on your own team and that many again on the other team their is so much noise and movement. Don't fool yourself that being quiet is doing anything. Yell yell YELL. The mask covers your mouth and ears. It is hard to hear over the sound of firing and breathing inside your mask. Yell and repeat. Call out the enemy locations with distance and direction. Use the 12 o'clock system. "Bob from you there's a guy 2 o'clock at 35 yards behind the blue spool."
Be aggressive. Work as a team. Identify where the enemy is and put fire on him. You can, no you must move under fire. But do it safely. Make short runs. Have your team lay down covering fire to keep enemy heads down. Know where you are going and why you are going there. Where an opening has presented itself exploit it. FLANK FLANK FLANK! Don't sit and trade shots with the guy in front of you. Look left and right and get the guy out shooting at your buddy. If possible have your team distract and pin down the enemy while you fall back 30 yards and come in from a different direction. If they didn't see you fall back it will appear that there are more of you than there are. The whole idea of ambushes sounds great but with 20 or 30 guys on a team it does not work. ALL guns up front and in firing range. Imagine just you and your one buddy watching a dozen guys coming at you. They WILL get both of you and you might get 1 of them. Not a good trade. Any group will wipe out an army if the army only sends 1 or 2 guys at a time.
I am 42 years old and play with my 20 year old son. He is as good a leader as i am. We always play on the same team but rarely see each other on the field. We split up. I take the left and he goes right. We each know what the other is going to do for the most part. We can each hear the others voice across the field and have an idea of what is going on without radios. You may come to the field to play with your buds but it is far more fun to tell each other stories of your heroic deeds after you won the game than to ask each other what went wrong and play the blame game all the way home. Beside if no one saw what you really did, you can exaggerate just a wee bit.
Talk to your team AND the other team in the stagging area. You should all be friends. This cuts down on hard feeling when the other team loses 10 of 12 games that day. As the day goes by people come and people leave so the teams are being reorganized. Be prepared to be moved to the team you have been stomping into the dirt all day.
I know this sounds very different from most of what is written here but it works for us. Yes we usually win 10 or more of 12 games played. By the third game people are saying to us " You do a great job of leading and directing. What should we do in the next game?" People like it when we win a game and we have 12 of the 15 guys we started with still on the field and the other team is sitting in the staging area.
Shoot Move Communicate