my experience is leaflets are not cost/ time effective, sometimes less than one job per thousand but does raise your profile in the area. advert in local press effective but expensive. door knocking, time consuming but effective. most work this year for me has been recommends, repeats which is great. after a few years you get well known and this generates income. to do this full time you really need to be looking at the commercial sector as well i would think and diversify. you can't rely on domestic patio/ drive cleaning to see you through the winter. also the weather this year has put people off. in south yorkshire we have had rain of some sort on most days since the middle of may, culminating in the floods.
just my thoughts
Ged