Just a couple of observations:
1) If you are married and stable in the relationship, have your spouse "own the business." She will pay your wages, she will do much of the paperwork (in most cases,) and as an employee, you get a bit better coverage both in labor laws and liability, (who owns your tools if you get sued.) If you are union, you get your union wages and health care. Here in Washington State, almost everyone I know in business for themselves "works for the wife." Both of you draw wages, so there is some form of tax benefit, (not sure exactly what, but all tell me about it.)
2) I would never work for cash, too often, people know the difference or think they do, so immediately you are at a disadvantage in negotiating the price for work. They offer 10-20% less than they would be willing to pay if not cash. The fellow that works on my car, (I'm not a mechanic by any stretch of the imagination,) refuses to work on a cash only basis. Cash customers assume you are working under the table and figure if you will cheat the government, you will cheat them. I bought steel at a small steel yard until about a year ago when the IRS and L&I shut them down for not collecting sales tax, not paying income tax etc.
3) You paperwork labor hours in most cases will equal your tool labor hours assuming you do everything above board.
