+1 on what phillo said. A few lesson I learned from my roofing business were, always have good quality business cards with you, these are generally your first point of contact with new customers so don't cut corners with these. A good van that's well signwritten gets you noticed as well as sign boards & don't make promises you can't keep.
You only get one chance to make a first impression. It's an old cliche but very true.
Good luck mate, hope it all goes well.