Once you get good at using the keyboard for input into your computer then it is certainly the most productive input device.
Until you memorise every single key command you could possible want you are going to need to interact using your mouse, which is fine.
If you find yourself doing the same repetitive task with a mouse I suggest investing 5 minutes into seeing if there is a series of keypresses you can make that would have the same effect.
As well as being faster, using the keyboard is going to be easier on your wrists and so long as you have a good keyboard then probably better for you in the long run.
If you insist on using the mouse (or trackpad) as your primary input device then here is my tip.
Speed up the tracking speed of your mouse
I personally like to set mine to the fastest possible, but try even speeding it up a slight amount.
It will feel weird for about 2 minutes, then you will feel completely at ease with it and other machines will feel like they are lagging when they don’t have their mouse as sensitive.
The main benefit is unsurprisingly that your mouse will move faster, this means you will spend a shorter amount of time moving between places.
Considering the amount of time you spend moving your mouse I am sure over the course of your computer life your wrist will thank you that you haven’t been dragging the mouse for as long as you could have been.
Changing mouse speed
On OS X you can do this by going into your System Preferences and opening up the Mouse pane.
On Windows you can do this by going to the Control Panel and selecting Hardware > Mouse