Communication is crucial when playing indoor paintball: constantly relaying information about the enemy position is of the utmost importance for you and your team when trying to keep an eye on the flow of the game. E.g. when you are at the right-hand side of the terrain and you spot enemies advancing on the left, inform your teammates of the enemy movement. This will hinder the enemy attempt at flanking your team and prevent them from getting some easy eliminations.

As paintball is a group activity, coordinating with your team is top priority. An ideal approach is forming small squads in which you can advance while providing each other covering fire. The quality of your teamwork will often be the deciding factor in your win or loss!

Make sure to keep an eye on both sides of the playing field. If your own team is bundled up at the same side and neglects the other flank, the enemy team will have an easy time executing an envelopment and eliminating your entire team.

Waiting for the other team to advance while hiding in your own camp, fittingly called camping, is not an efficient strategy. Attack is the best defence! Moreover, if the enemy team does the same, the game might become very static which does not make for the most exciting gameplay.
Keep moving. Hiding in the same spot for too long will make you an easy target for your opponent.