What I would do if I get lower than average preflop, flop cards:

1: With table-games
(1) Switch tables. More times than not, I realize the dry spells are a comination of the ppl at the table and the hands you receive
(2) Lower my goals to break even and quit poker that day. Normally I shoot for sizable profit when playing any given session.
(3) At tighter tables, you can try betting a bit more looser. Especially good if your in position, but even out-of-position, you should be able to pick-up some extra hands just by betting more at tight tables
(4) At loose tables. I would personally just switch tables. You could try overplaying your strong preflop hands (e.g. go allin with AA, KK). Sometimes a whole night of dry hands can pay off with a fish calling your all-in AA
(5) If your online, try playing multiple-tables (2-3 windows open). I find if I dry-up on one, the other 2 are more than enough to make it entertaining.
(6) I also have a tv tuner and a small resolution setting so I can play 3-tables and watch tv when play gets dry.

Personally, my stats show I fold 50-60% of the time. Having dry spells could also be a subjective view vs playing patiently