As part of my martial arts training in Dundee, Scotland
I focus primarily on moving, by practicing the basic stances and turning movements.
I tend to place particular emphasis on my weight distribution and the feeling of being grounded (one with the ground) whilst retaining perfect balance.
After this I have found a number of ways to simulate having an Uke by practicing techniques such as Irimi nage, in a door frame.... i.e. by practicing irimi from various distances into the wall. Practicing in a door frame means that you can use the wall to simulate a strong opponent. You enter, extending your arm to the wall (as if it were around Uke's neck and upper body), squaring your hips off against the wall etc...
I have found performing this and a number other techniques against the wall invaluable in my daily practice, as few things are as unforgiving.... Practicing this frequently fosters a strong technique that works against otherwise immovable opponents.