Scheduling

Somehow, scheduling in real life works much worse than on my 5 PCs with 6 CPUs currently (soon 7) - I’m constantly feeling that I’m not doing as much as I would like to, let alone as much as I could do. For example, a second project I recently started is still hanging around as I can’t focus properly on it. Bad thing is that it’s scheduled for release in december. I’ve been using Microsoft Project to schedule my work hours once, but that didn’t work out that good. What do you use to max out the time for doing useful things?