There is worldbuilding and/or writing that I know I need to do, and even want to do on some level, but I keep not doing it. I don't have what I think of as traditional writers block, because I'm not even getting as far as looking at a page that I'm not writing on. I'm not even putting off what I need to do by doing other things (until I started typing this question), I'm sitting doing nothing when I know I need to reread some notes and then do something; either writing more of an existing narrative or do some ancillary worldbuilding work if I don't think things are quite ready yet.
My question is how do people get themselves moving when they know they have work to do and time to do it?
Any suggests for techniques or tools that make staying on track with writing projects easier much appreciated.