Make your flyers/leaflets as visual as possible, keep the wording short and simple, if you mention prices use a phrase like (Diveways & Patios Professionally Cleaned From £70) or whatever your minimum charge per job is.
Delivering leaflets can be very time consuming or expensive. What i do now is advertise in a local monthly full colour A4 glossy magazine. The magazine is very professional looking and i know that peaple keep this publication for several weeks (unlike other local free papers which are thrown out after one day) and use it when they need local tradesmen.
I pay £300 Plus V.A.T. Per month for a half page full colour advert, and the magazine is distributed to 23,000 local businesses and homes each month from this i get at least 30 leads per month most converted into jobs. In my mind money well spent.
If you decide to advertise rather than use leaflets just be very choosey where you spend your money.
Regards
Mark
P.S. Get your van sign written 4 sides wording only about £160 cheap advert 24/7