I can't play good doubles unless I've really practiced. I can play decent singles even if I don't pick up a racket for 3 or 6 months, but doubles is a whole different story. The skill set for doubles is different and I can't make up for weaknesses the way I can in singles.
Like in doubles my return of serve, serve, and volleys have to be on, and those are three things I rarely practice. I always feel bad when I take volleys, like I'm forcing the player at the baseline to cater to me.
But I was a really good doubles player in college. I love targets. Get somebody at the net and all of the sudden the pressure comes off.