Are you practical? You may find yourself with up to five or six months a year with few or no clients. The cost of repair work or new works can be a large part of your outgoings - how much you can claw back into your profit margin depends on your practical skills. DIY bodgers will not do, you cannot have forty guests waiting for a hot shower whilst you fumble with a fitting, on the other hand if you can gain genuine competence then you can save a fortune.