Concentrate on creating pretty, aesthetically pleasing patterns with your pieces.
Hanging your Queen was all the rage in the middle ages, revive this custom.
Try to mirror your opponents move at all times, if this becomes impossible, concede.
Close your eyes, stand up, spin yourself round on the spot 5 times. With your eyes still closed, aim your hand at where you thought the board was and pick up a piece, deposit it back down somewhere else.
Refuse to improve. Aim low, achieve lower.
Under no circumstance allow your Pawns to support each other.
In the unfortunate instance of acheiving Pawn promotion ensure that the promotion stalemates your opponent at the same time where possible.
When playing superior opposition - just quit after 4 moves, save them their valuable time in having to beat you properly.
Use your nose to pick up the pieces by inhaling them into the nasal passage, then deposit them back to board with a generous nasal exhale. If the piece in question re-appears wearing a green or maybe yellowy 'hat' then so be it.
Hmm, second thoughts - that may not lose you the game, but it might earn you a tremendous physical beating at the hands of your disgusted opponent!!