If you like using shortcut keys...I have found adding a gaming keypad to my system helpful. These keypads have programmable keys that enable tool and/or procedures. The unit I use is a Razer Nostromo with 17 keys. Each key can be programmed with a shortcut or a macro (multiple key strokes). There is even 8 levels or layers for each key giving you 136 keys to program (although I find this overkill).

I programmed all my most common tools used in the drawing process. I memorized the key locations quite quickly. Keeping my left hand on the keypad and my right on the mouse, drawing speed has increased nicely. Just remember to do some finger/hand stretches. Carpal tunnel is always been a problem with CAD operators.