Find a spot with only one or two directions enemies can come at the team. Over the next weeks people will be trying to find out the best cubbyholes.
If relying upon archer longshot spam, stay in a location where ranged enemies will come up around the corner FAR frm the team.
If not relying upon archer longshot spam, stay in a location where ranged enemies will come up around the corner NEAR the team.
Stick together, if a teammate can barrier, try to stay within range of barrier.
Either focus down the boss fast or have someone kiting/fighting him while the rest of the team farm more spawning enemies. If vs. Red Templar kiting, keep him in phase 1 during the kiting period by not lowering his hp below 80% so that he doesn't use any special abilities.
@Bioware: Good job. Played several games with top 100 leaderboard players and sometimes we were going down like flies.