I expect this has been done in past, but I thought it might be useful to get a few top tips in one thread. You never know it all I figure!
My top tips may be fairly obvious to some I guess, but anyway.
S.A.E - With regards to collecting. I have a very established round, and only work for people I trust. I collect every 3 months with a stamped addressed envelope through the door. That stamp costs about 12p a month. I have found the customers love this non hassal form of payment no end.
WFP - Don't believe the hype. If you have a good thing going with trad, don't feel its a necessary progression. People will tell you how great it is, and often gloss over the drawbacks. You can still make a killing with a ladder on the right round.
Price high - Bloody obvious I know, but how many times when you start out do you get asked for a quote, price it too low, and end up with a job that is worthless to you down the road. Take a bit longer and get high quality work.
Canvass the work you want - I got set in my ways for years doing residential work. One day I took a day off and touted a small industrial estate. I got 10 hours work - which is now 15 after people saw me about. Priced at 35 per hour instead of the 20 I was getting for residential.
Gutters in the rain - When you get guttering jobs, tell them you will do it when it rains. Stick your waterproofs on and away you go.
Be pleased to hear any other tips others would like to share...