They spell this out very clearly in Kevin Bupp's pod casts.

Cash flow is difficult here in California, and so I'm looking for opportunities that have strong appreciation and long-term growth opportunities with strong tenant bases to complement my long-term investment strategy.I appreciate any insight and stories.

I've paid for a handful of programs over the years from cheap to expensive and narrow-focused to broad-based. 

@Patrick Hancock let's touch base next week

Loan interest is deductible based on it's use-not the asset securing it. 

They benefit based on the interest rate.

Another option is setting a utility charge per unit based on square footage or occupancy.

As I take in as much content as possible from listening to the Rookie Real Estate podcast, I feel drawn to building multi-families and renting them out.

Just an FYI to everyone like @Tom Dieringer said, this is a base contract for anyone who wants somewhere to start.

Base your decisions on hard facts only and maintain a paper trail.