...what's your secret?

Mine is to be very careful NOT to overcook it. Game meat is very lean, so cooking it beyond the med-rare stage just defeats the whole idea of a tender, juicy bit of meat.

Steaks - just on the bottom side of medium rare.
Roasts - just into the medium rare stage, no further unless it is a cut that requires long, slow cooking as in a crockpot.

Stewing cuts are - of course - exempt from the rule because they need that long, slow, wet method of cooking.