I just run around meleeing enemies when I get placed in a hopeless Gambit match with morons on my team, playing against a fireteam/clan that invades every 2 minutes with Queenbreaker or One Thousand Voices.
In Crucible, I at least try (and usually do better than the rest of my team), unless we're getting completely stomped. Then I start jumping off the map until the match ends.
Atleast play the match my guy. Nothing irks me more than having a teammate who’s not pulling their weight. Last gambit match I went into had a guy walking up against the wall and he costed us a round because of that. Not lag it was because of the breakneck bounty. If you can’t bother to pull your own weight at all then don’t bother going into a match
Just grab the bounties and play to those. It's only 5 matches a week (6 if the daily comes back after the Saturday reset). I just grab the bounties before I hop in. Gives me something to do.
Occasionally I'll participate. A lot of rounds I'll just sprint and hammer strike the one guy in the match who isn't using a shotgun. Obviously dying to all of the people who are using shotguns.
The fastest way to get the engrams is to get mercy ruled, though.