I just go with the flow, honestly. If I wake up at 3 or 4 o'clock in the morning, I'll attempt a WILD. If lucid dreaming is a major topic on my mind throughout the day, I'll try to MILD later that night.

Surprisingly, this has been a very effective way of attaining lucidity. Many dreamers take these methods far too seriously and end up stressing themselves out, which in turn detriments both their motive and their effectiveness at lucid induction. Do whatever works for you, though! Try every technique, "play around" with sleep schedules, and take it easy on yourself.

To answer your question: EVERYTHING!