Any capital improvements on a not owned yet property would involve a complex 1031 you’d want someone like @Dave Foster involved in. 

Personally If you like your current residence and hope to stay there long term I would forgo major improvements on my primary and use all investment savings to make you more money and cash flow. 

Offering discounts for weekday or longer stays could also help improve occupancy.

Sure, I could look for a higher paying job, but I was wondering if anyone has any creative short-term methods to improve my ratio.

They will improve, but never "pop."

What are the best areas of a single family house to renovate that will have the greatest improvement to home value?

@Kyia Raiford, I concur with the advice mentioned above.

if so that's going to be a deal that needs significant capex improvement to hit those margins.  

And sometimes, we are not materially improving what you could have done  yourself. 

It's a great way to showcase the improvements made and helps appraisers not miss stuff.