Good luck, I use my parish magazine. Most of the tradesmen we use are found there, and none of them has ever let me down.
Your local Age UK may well also keep a list of tradesmen for local older people to consult. I would emphasize your presence in the advertising, many old and vulnerable people feel much safer when a woman is involved in doing anything in her house.
There are also online directories Checkatrade, I have no idea what they charge but a lot of people use them. DD uses them for eveery trade where she doesn't know someone local, again, with good results
Other things to do are to print leaflets and go round stuffing them through doors and put them on local noticeboards at shops.