Premove your king on the opposite colour squares. If you have a pawn then there's probably a silly helpmate in there somewhere. For instance if the queening square is the right colour then you could have this:
Silly, but there you go, not impossible.
Me: king + pawn on the 7th rank, Opponent: king (in front of my pawn) + bishop.
I guess there's a reason why this was not rated a draw when I ran out of time (though I don't get it how he should have mated me), but I don't think it's very sportsmanlike when he uses his 20 more seconds to stupidly move his bishop around the board waiting for my time run out doing the same and declining a draw :-/