Start off by targetting wh at you already have - oven clients and "spring clean" clients.
Offer them an incentive to refer you to their friends, family work colleagues etc ie £10 off theit next clean for every "friend" introduced who has a carpet clean.
Then offer these referals the same incentive, and so on. Takes time.
If you not busy doing ovens and spring cleans, why not deliver leaflets yourself. Perhaps knmocking and introducing yourself. Failing that just deliver. Then repeat same addresses a few weeks later.