For my animated asset in this game module, I thought it was important that my sushi bar spun around. At first I rotated the bar at the speed I wished it to be in the first 12 frames (half a second), and then extended this for a little longer to check I was happy.
I then calculated how many more frames would be needed to allow the sushi bar to do a full rotation. Using key framing made the animation of the sushi bar reverse backwards and spin at unusual rates as it didn't do a full rotation in one direction and rotated the other way too! So to combat this I deleted the key frames and once I had worked out the length the rotation would take, I simply used the start rotation as 0 and finished at 360, ensuring that the animation would be rotating in the one direction (which worked!).
This then took me on to the graph editor, where I adjusted the easing, and made the points completely straight which allows the bar to spin at a constant speed.