I think the important thing is to have some measure of self-control; if you buy a domain for a project, promise yourself that you won't buy another until you've

I think the important thing is to have some measure of self-control; if you buy a domain for a project, promise yourself that you won't buy another until you've either: (a) built the project, or (b) sold/traded the domain or otherwise used it in some gainful way. Disclaimer: I've got a bunch of domains that I purchased for personal projects and never got around to. But at some point, I realized I was just wasting money and promised myself not to buy any more until I finished at least one of the projects.