Basically, increasing your leverage means to take on more debt/loans.The BRRR method is usually associated with increased leverage, i.e. more loans. 

We updated the plumbing and electrical, gutted the kitchen and bathroom, refinished the amazing oak floors, added new hardware and lighting, and painted inside and out.The finished product turned out great, and after 2 days on the market, we accepted an offer $9,000 over asking price.

We updated the plumbing and electrical, gutted the kitchen and bathroom, refinished the amazing oak floors, added new hardware and lighting, and painted inside and out.

However I am extremely committed to this and would like to move into mastering the BRRRR method and learning that portion of real estate investing.

Another option is to inspect the major items like roof, mechanicals, plumbing, and electrical ahead of making your offer (assuming you are confident you can get it or willing to risk the costs of said inspection without a signed contract).

I am not an attorney, but at a minimum, you're going to need (1) adequate property insurance, (2) a standard lease agreement, (3) a method for vetting tenants/doing background checks, (4) a method for collection of rent, and (5) possibly a license for the property to be operated as a rental (you will have to check the requirements in your jurisdiction).

You can read my Google reviews for Scenic City Plumbing and Foster Electric.

Any tried and true methods? 

I can think of HVAC, plumbing, electrical...

I also heard investors don’t like personal checks because tenants might say “it got lost in the Mail” let me know your methods!