Okay well if you do wing chun that is great, so do i! Yes it is definitely worth practicing alone. Here are some of the things i do:
Get a 3 section wall bag and a wet towel (with somewhere to hang it). Assuming you have correct form on your sun fist punch, you should practice punching the center of a wet towel with out any water flicking back onto you. And with the wall bag (if you can not get one or have no where to put it, wrap towels around a tree) repeatedly throw a strike of any kind and a block to accompany it. This is good for muscle memory for striking and blocking. For example, tan sau and straight punch, switch to bong sau with turn and back fist, then lap sau and low punch. Basically just combine attacks and blocks as you hit the bag. Also practice chain punching and following up with kicks and strikes from different directions.
Also do you know the forms Siu Lim Tao, Chum Kiu or Biu Jee? Practicing the forms slowly, as in taking half an hour to complete the form, will be excellent for training your stances. If you are proficient with Siu Lim Tao, try doing it on one leg.
Also footwork drills are very important. Repeatedly practice short steps, long steps, (both with and without switching feet), changing direction, moving sideways etc.
A good footwork drill (and later on, handwork drill as well) it to imagine a clock on the floor. Your opponent is at 12 and you are at 6. Start in neutral wing chun stance, practice stepping to different numbers, whilst keeping your front foot and your stance facing 12, and then step back to 6. After a while, start doing this with an attack as well, just remember you always want to be facing your opponent at 12 and make sure you have your weight aligned properly on each foot. If you have not done this before, start slowly.
You will be glad to know you can become a good wing chun practitioner without ever sparring or fighting, all it takes is dedication. And you can practice anywhere, you can practice wing chun standing still, at work, in the shower. If you want room, go find a park or field, or a small woods or forest somewhere.