-Never beacon when it is a close game with a few mins left, if your beacon gets disarmed this means 300 Pts for the enemy.I don't know how many close games I lost because some n00b keeps planting beacons with 2-3 mins left on islands giving 300 pts a pop to the enemy's side!!
-Never beacon when there is only 1 enemy building left unless you are able to hold them off from disarming it by having a tank to protect it or what ever.. Do you realize that when there is only 1 building left where do you think they will look for the beacon? And since its the only building left all of there soilders will be in or around it which means it will most likly be disarmed!
Just because you have an extra 1000 don't mean you can go running around with stealth black hands and planting them everywhere, be smart when and where to place them.. In a close game 300 pts usually means the diffrence between winning and losing!