I started 'full time' straight away from scratch when I left the army.
I had a few grand stashed away that I used to pay the bills with, supplemented by a weekend night time security job that paid peanuts.
I took Mondays off (to catch up with sleep from not getting much kip from Friday to Sunday nights) and cleaned windows or delivered flyers for the rest of the week; I didn't have the balls to canvass to begin with (though I wish I did).
Once my savings ran out, we were truly skint. It was an 'orrible time and I commited just about every crime there was when it came to UNDERPRICING (don't do it; you and your customers will suffer for it).
Five years on, I've just had to sell a lot of work and I still can't keep on top of it.
Good luck.