One word of warning though.
A lot of handymen do tend to struggle getting regular work, its very up and down.Makes future plans more unstable in an already unstable climate.
If you ever need to borrow money from a bank, they won`t want to know you without a Fijo contract, especially difficult for mortgage and loans.
Autonomo is ok if you can get work and grow quickly or if you`ve invested a lot of cash into a professional business.
Many Spanish institutions are well aware of foreigner Handymen.A friend of ours last year, got told by his Bank manager to come back when he got a proper job and he was a landscape gardener and needed a new vehicle.
You`d be surprised how many Banks got stung by foreigners borrowing a few thousand Euro`s only to see the borrowers do a runner back to the UK.
If you can live day to day or week to week it`ll be fine, but you could find your broke next month.
I did it a few years ago when I lost a job, it filled the gap, but I wouldn`t live that way personally.