In case you are not aware of the know/how of CSS3 transitions here’s a link to know more about CSS3 transitions.
A lot of designers have started creating their own Cubic bezier functions, here are some of my favorite ones:
1. Easing Out Back : Standard easing one but one of my favorites : cubic-bezier(0.175, 0.885, 0.320, 1);
2. Pause and Go : Stops in the middle : cubic-bezier(0.765, 1.005, 0.260, -0.020)
3. Kick Back and Start : Starts with a kickback : cubic-bezier(0.815, -0.345, 0.305, 1.055)
4. Elegant ( Slow start & Slow end ) : Used by Kriesi in Themeforest Top seller : cubic-bezier(0.175, 0.885, 0.320, 1.275)
5. Kick Start and Ease out : cubic-bezier(0.775, -0.365, 0.255, 1.430)
There are a lot of tools out there to try out your own transition, here are couple of links where can try it out :