Any text editor will do, main thing is that it's super quick to write things down. GTD-stuff is overkill for me. I found that keeping a list of ideas will clea

Any text editor will do, main thing is that it's super quick to write things down. GTD-stuff is overkill for me. I found that keeping a list of ideas will clear my head to be open for new ideas. Otherwise my brain will use a lot of memory/CPU to keep the old ideas around. Second thing I found useful is to expand on ideas when I have some time. I simply take one and write a whole document on it, detailing design, features, purpose, value, target market etc - anything I can think of. I keep revising those randomly. The good ideas stick and turn into documented project plans over time.