Cards Needed:
Time Wizard
Mirror Force
Any Monster (preferably powerful)

I use this tactic all the time when I duel.  All you need to do is set Mirror
Force, then play Time Wizard and use its effect.  If you call the coin flip
right it destroys your opponents monsters and leaves their life points wide
open for direct attack with a powerful monster.  If you call the flip wrong
you lose your Time Wizard and 250 life points.  Obviously your opponent will
be inclined to attack in which case you use Mirror Force, which hopefully
leaves their life points wide open for attack (that is unless they have a
monster in defense mode).  Either way it does good things for you.  The 2
drawbacks are losing 250 life points or your opponent having a monster in
defense mode, preventing you from attacking their life points directly.

If you have any questions or comments contact me at djmtanner@earthlink.net.