Since the funds are business credit, you wouldn’t have to worry about personal financial strain, and it allows you to keep your capital intact.I’ve seen investors use this method in various ways: some use business credit cards (with 0% APR for 12 months) to pay for renovations or bridge loans, others use business lines of credit to cover larger gaps.

I think a heloc is a solid method to fund a flip.

It might not be the best method but it works for what I own because I only purchase performing notes. 

Quote from @Paul Lucenti: Creative methods tend to increase risk.

Unfortunately, while there are other methods to acquire investment properties, the reality is you need cash and reserves to plan and set up your investment portfolio accordingly. 

Have you done any research on what method of investing you would like to do?

Structuring Financing for Volume-Based InvestingTraditional financing methods like hard money loans work well for single properties but can be less efficient when you're scaling up.

It’s a strategy that allows investors to acquire rental properties with little to no money out of pocket while building equity along the way.If you're considering using the BRRRR method to grow your real estate portfolio, here's everything you need to know about how it works, its benefits, and potential risks.What is the BRRRR Strategy?

Yes, comparable sales is one method for appraisal.

For all methods you would want to find a market that has strong employment rates, strong income rates for the market, and is a growing or an established market.