I've been writing full-time since 1978.
Freedom is just Chaos, with better lighting.
Don't try to write to the trend of the moment.
I try to challenge myself as much as possible, as often as possible.
I hear entire symphonies, oratorios, in my head, but I can't write a note.
How much research I have to do depends on the nature of the story. For fantasy, none at all.
In one book, CACHALOT, just for my own amusement, every character is based directly on someone I have known.
I write early in the morning, usually after reading portions of at least half a dozen newspapers on the web.
I have a bad tendency to get rapidly bored with my own material, so rewriting is hard for me. I mean, I already know the story and would rather read something new.
Advances have fallen, generally, for everything except the biggest potential bestsellers. Given all the changes, both economic and technological, SF hasn't done too badly.