Mike Schultz, retired builder, shared these thoughts on rehab projects:

While rehab (fix and flips) is a great way to make money, be careful to not fall into these traps:
1) Don’t overpay for the property you are buying. It will always cost you more than you think to rehab, so pay less than you think you can for properties. Buy well.
2) Work quickly. No project that takes too long makes money. Get in and get out.
3) Don’t put the property on the market until it is 100% done. When customers come in mid-stream, you end up spending more to finish the property to their specs, and typically make less and take longer to finish.

This is a great way to make a living, but remember, this is a business.