Here is how I financed several properties:
1. Turned home into rental: not really a house hack as I didn't realize the house would make a good rental until after I brought it. It was my best performer last year.
2. Purchased a condo worth $30k for $18k: Signature loan (personal loan). No money down. It is in an area that was gentrifying. It was renting at $550. I just updated it and signed a new tenant at $750 per month.
3. Condo for $30k: I financed this one with a small credit union who did small in house loans for properties under $120k. There niche was old mill houses which often sell for $25k and had no problem with my condo.
4. 3 condo deal: Financed them together using a business loan from another credit union. This lender became my preferred lender.
5. House Hack: I moved to a different part of the state about an hour and half away for my husband's work. We brought a small house that looked to be a good rental to live in until we knew what we wanted to buy. 5% down conventional with a no PMI deal. I can't remember why no PMI, but it was great. I am under contract to sell this one currently.
6. BRRR House: This was a no money down deal. I left with a check at both closes. I used the preferred lender above who gave me 80% of purchase price plus 100% of rehab per contractor quote for a fixer upper that I turned into a rental. I left close with a $12k check as the house was purchased for $59k and had a $26k rehab budget. The bank gave the rehab upfront instead of in draw form. I used 18 months same as cash credit cards to pay for the work. 2 months later, I refinanced it for $107k loan and left with a check for $30k which paid off my contractor and any other items put on credit cards.
7. Duplex: The about $13k I had left from the original was rolled into a duplex I purchased. Also, I had refinanced the package of 3 condos buy then as well. I got the duplex for $60k. This loan was under my lender's limit, but I had done several deals with them at this time and the bank let it happen. I put about $5k into the property. It rented for $650 and $750 ($1400 total). I sold it for $92.5k last year (18 months later).
8. Rinse and repeat. Establish a relationship with your lender. I thing I have done something like 7 or 8 mortgages with my preferred lender including refi's.
9. HELOC: I purchased my current home as initially a live in flip as I purchased it $40k under the appraised value. The house was too big for us, but before I even made the first mortgage payment I was pregnant with twins. I decided to stay as we needed the big house now. I got a HELOC on it for $30k back in 2016. I used that HELOC to pay off the signature loan on the first property reducing my interest rate. I then rolled that first property into another loan I did with one of my houses and then used the HELOC gain for another purchase, though I forget which one.
Hope this gives you some ideas. Also, we did this with not a huge income. I am an accountant, but I have not worked full time since my twins were born in 2016. My husband is a teacher.