Wouldnt recommend doing it from your garage, unless you have a pole barn or something.
I know 2 people that have their own shops. Person A runs his out of his attached garage and gets no business. He tries to promote It on facebook but looks like a shit hole and there is no room to park cars inside it, or on the street. Person B has a pole barn, with a lift. He sees 5-10 "clients" a week. Word of mouth is his only source of advertising. He tried to put up a sign but zoning restricted the idea.
Also, don't forget the liability aspect of things. Waivers, forms, etc..
Just some food for thought.