I've known about Hammer for about 3 years and I've always wanted to make a map for TF2 or CS, maybe even HL2. The thing is, I've never been able to do it. I've watched and read many, many tutorials on many subjects in Hammer so I feel I have the technical skill to at least work through some alphas, but I have no ideas. I can't figure out how to start a map and block out a layout that's all my own. I think I'm so afraid of making something bad that I over-analyze every brush I make right from the start. I don't know how to proceed.
How do you guys start/plan your maps?