I work on at least 5 projects at a time. I set guidelines for myself and usually spend a week at a time on each one. It works for me as many times I like to mull over the next step in the project. It also gives me something "new" to work on all the time. I do find that once I reach a certain point I tend to concentrate on a project and get it completed. The good thing is then I get to work on another one! All my UFO's are in acid free containers with the instructions, specialty rulers, etc. I usually leave myself a note as to what the next step should be so they are easy to pick up and work on.