Here's something I tell my buddies. Before resigning the game, if you have mating material left, start throwing them around the enemy king.

I've been down a queen on a few occasions over the past 30 odd years. I still remember three times against "A" players where I was able to pull off a victory from the clutches of death. Against Expert and above I'm not so lucky

I agree with Perseus on the counting system. Treating pawns as a point, a queen is worth 9 points. That in mind, try to gain compensation for the loss of the queen with a combination of misc material such as the opponent's 2 rooks (10 pts) or a bishop, rook and pawn (9 pts).

Remember to keep your pieces active and have fun.