This is a well documented shortcut, but I find it handy pretty often (especially in post-production), so I figured I’d give it a mention.
To enter Shuttle Mode, hold down Control, and hit any number on the number pad. After you are in shuttle mode, the control modifier is not necessary for changing the speed.
The 5 key is normal playback speed
4-1 are progressively slower
6-9 are progessively faster
Hitting the +/- keys will toggle between Forward and Reverse playback, respectively.
When you are done shuttling, hit stop and you will return to normal functionality.
I find this pretty handy for checking sync on sound effects or dialog.

