Tried to search, but found no similar topics. Very sorry if this is already posted.
If you pop spell reflect and type /sit (or make a macro) you will keep the spell reflect buff for full duration, even if you are getting hit with several spells. Very useful vs 2nuker classes in 2v2 arena.
Combustion bug is similar. Pop combustion, get a few non crits, the higher the better. Cast fireball or pyroblast, and when the fireball is in the air, use the /sit macro. When the fireball lands, and crits, you will not lose a combustion charge! Only downside is that you wont get ignite proc either