I've learned to not start too many at once because then you've got multiple projects behind. It's even more frustrating that way. Each project inevitably takes longer than planned, so whatever is in process will inevitably be behind, but whatever is done is done. I've got a ton of spring and summer projects lined up, but I'm at least not frustrated with all of them yet.
Case in point: My truck is nearing the end of its TLC. Lots of tear down, rust repair, body work, etc. Last cab corner goes on tonight and body work wrapped up by end of tomorrow night. Should be spraying paint Friday night or midday Saturday. Then reassembly. Took longer than planned/hoped but its almost done. Since it took longer my camper maintenance and flooring, along with my pool deck, are all now behind schedule before even starting. But in a week I'll have 1 project done and 3 behind schedule, which is a lot less painful than 4 projects all behind schedule.