The best physical practice is a CS-timer session it's efficient accurate and fun.
but be careful too much solving at one time can be bad. See mental practice for more details.
If you have more than one 2x2x2 do a relay it is a fun way to teach your hands to start solving as soon as you pick up the cube.
If you are not amydextrias, like LNBFilms, which I assume you are not, you should try doing finger tricks with with your "non-dominent" hand. For example, do double flicks with your non-dominent hand, you will get better at them.
Try doing an average of five (or average of "X") once, write it down, then do another one, and repeat to see how much quicker your times will become!