Mario Kart Wii/Flower Cup

Mario Circuit
Use a mushroom only to skip the chain chomp, and to also go off the ramp.

Coconut Mall
There are several places where you pass a pair of moving escalators. One goes in the direction you are driving, and the other in the opposite direction. Pick the one which goes in your direction, and you receive a speed-boost. You will slow down if you drive over the other one.

Watch out for the cars near the end of the tracks; if you get hit bye one, you will lose your items and lose a lot of time. Avoid these at all costs!

DK's Snowboard Cross
After you land at the top of the mountain, you will encounter a ramp, and after that some very dense snow. You will slow down tremendously in this snow, so unless you have a mushroom, star, etc. avoid this.

Near the end, you will enter a half-pipe with some shy guys. Avoid the dense snow and follow the blue parts at the edge of the half-pipe.