There are many directions you can take this business. If you want to work during hours when no one else does, you can focus on office clients. You can focus on retail businesses and keep your customers clumped into one or two blocks. Restaurants are in great need of daily thorough cleaning and can be a great source of steady clients. Perhaps you would be more interested in house cleaning. Many times with cleaning services you don't have to spend lots of money on advertising or marketing because your customers will come by word of mouth.
Do you love woodworking? Even without a huge workshop, you can create some of the more popular crafts and sell them. And like most things, your success in business isn’t necessarily related to how skilled you are as a woodworker. So if you can figure out which products consumers want and just create those, you could have a good business plan. Etsy.com and farmers’ markets are a great place to start selling.