I often will go through the movements of a technique with an Imaginary partner and really focus on things like foot work and lowering myself as these are my weak points.
Also tenkan practice, Tenkan in 4 directions, low Ukemi.
Read all the books I can get my hands on and view DVD's on the subject as I can get copies on loan or bought.
Heck I find I even practice in my dreams and am often caught daydream practicing when I have a spare moment.
Yeah I'm maybe a bit addicted.