My parents took out a HELOC loan on their house, and I managed the property with a 50/50 profit split. 

This seems very appealing due to the monthly saving cost when compared to a heloc or other loan options.

It's good that you have the HELOC option though.

Build equity, get a heloc, and get another house.  

I also did a cash out refi and HELOC on my primary to snag another 5 rentals.

Tell us more about financing the down payment…did you use family/friends or a HELOC on another property or something else? 

The first few years we used HELOCS to make the down payments on our buy and holds, as well as down payment on a flip.

Should i do a heloc or cashout refinance.

You have a number of ways you might be able to finance multiple down payments — potentially through partnering with investors or using HELOCs on your existing properties, possibly even seller financing.

You’ll use the banks money to completely fix it up, also increasing the equity of the property which comes in very handy when you’re ready to refinance to get rid of mortgage insurance, potentially pull a heloc, or just be more bankable in general.