I did ceramic tile backsplashes for a while. Condos and new construction, you send the homeowner off to select tile, you pick it up, as a contractor you should get 5-10% discount. Its clean and easy work, no bending over, use premix adhesive so no mixing. I had an inverter in the truck and ran a small tile saw in the back, cutting and mess stayed there. customer gets billed for corner trims ect. , the leftovers go to the next project. You have to go back next day to grout so its a 2 days project, 4-5hrs to tile, next day 2-3hrs to grout and clean. I could net $800 on a splash in a nice kitchen, made a good sat/sun. The layout is important , as is straight clean work. Don't do your first job in a customers house......
I now do custom rope splicing for race sailboats, tech lines like spectra and dyneema, end for end splices and eye splices and tapered sheets. Its a very niche market but lucrative, and I do some electronics installs and some marine diesel work. And custom mast setups for race boats, tuned masts. Its interesting work and I get to spend time getting paid to sail.
And i build custom peppermills, don't do that......