Set your autopilot to sail a constant TWA and play with sail trim and watch the AWA and knot meter
Then set it to constant AWA and do the same thing (watching TWA instead).
Go up the mast and take pictures
Maybe your passages aren't long enough? I've found that the entertainment virtually takes care of itself after the first day.... either the weather forces you to be "on" or you've managed to get yourself into all sorts of stupid games/competitions with the rest of the crew