Process of writing a book

Despite all my real life aggravations, I'm feeling rather pleased with myself. I've just more or less finished the book I was (re)writing over the Christmas period. I have no idea if I'm
a) exactly the same as every other writer
b) fairly typical or
c) weird
but my books appear to develop according to a pattern - bearing in mind that I'm a novice and this pattern may well change radically. When an idea is buzzing in my little brain I'm never without a pencil and paper, in case words flit into my head and I have to capture them before they vanish into the frightening abyss and crannies of my memory. (It's so great to be blogging not writing - I can reiterate and repeat myself, and rabbit on without restraint - sense? what's that about then?)

This is my pattern (at the moment) -

1. Have what I think is going to be the main idea
2. Wiggle my fingers on the keys as the main idea writes itself out
3. During stage 2 find another idea/character develops along the way
4. Mesh the two ideas/plots/characters together
5. Realise something isn't working (1st panic)
6. Rewrite the whole thing, cutting out about half the MS
7. Fear that it won't be long enough (2nd panic)
8. Fill in the gaps and work out the details
9. Realise that it is going to work out after all
10. Polish

Amazingly, ten stages. (OK, I made it work out that way.) Rereading the 10 steps, it does look very unnecessarily complicated.

Question - is this how other writers work? Is every experience different or do you have a customary way of approaching writing, and if so, is it anything like mine? And if not, perhaps you can help me to find a better way?