One of my favorites have always been the Lee Sin flash/ward jump (behind enemy) - Kick into team. Pretty reliable, and helps out a ton in team fights. Flash/Condemn on Vayne is always a fun one.
Another good one that a lot of people pass up is simply, the power of the basic attack. First, choose someone like Teemo to practice with (You'll understand in a bit.) This trick involves getting the absolute most damage possible out without taking any yourself (or very minimal). All it is, is landing a basic attack and using an ability right after (Like Teemo's blinding dart.) The best way to do it is to get right in basic attack right (for instance, just right click on someone and let yourself walk towards them) and as your basic attack goes off, activate your ability, then walk out without getting any closer... Mind you, it takes decent reaction time to do this. When I do it, my basic attack animation is usually about 3/4 finished when I activate my ability (for this example, Teemo's Blinding Dart). It should be quite quick, but it does a lot more damage than expected. Do this repeatedly and you'll win lane in no time.
I do this a lot with LeBlanc too (especially between levels 1-6), basic attacking then activating my Q to get a good amount of damage.
It's pretty universal, a lot of champions are capable of doing it Like Ryze (basic attack + Q) Pantheon (If you're chasing, Basic attack + Q + basic attacks) Urgot (Basic attack + Q) Vayne (Basic attack + Q + Basic Attack) You get the point, right?
Hope this made sense, and If it did I hope it helped.. Good luck!