Well, I always start with the least-used things. They rarely come back out after you put them away, helping you to create space. I work my way up to the most used things.
If you do it the other way around, you will put the most used things away, but then they will come back out, and you won't feel like you accomplished anything. Meanwhile, the little-used stuff is still taking up all your space.
Another cleanup trick is to ask myself, "What one thing can I do?" With that, I can usually do one cleanup task, especially short ones. Once I've done one, then I can usually do more.
Another bit of cleanup advice: when you feel like doing something, do it RIGHT NOW. If you put it off, then you will soon feel like not doing it at all, so you may as well take advantage of your mood.
Put a "value" on your space. Some places will have "high" values while others have "low." Make sure that your high-value spaces are usable.