My landlording skills need some tweaking ...

I feel that timing matters more than strategy when it comes to investment; but when I miss the timing, I can only play with tweaking strategies which is easier said than done.

First a mindset tweak I want to make, then to the meat and potatoes of your question: don't worry about it being "too late". 

If you tweak your financial model too far in this direction you will populate your portfolio with properties that can potentially cost you money to operate.

Find (and there are a few excellent ones right here on BP) a real negotiator to handle it for you as an investor. lastly, excuse my tone, I'm tweaked out on Rockstar :) my drug of choice these days.

It can be same as a normal rental lease, with tweaks for roommates.

Tweak selling prices, rent, repair, ...and from what I play so far, it's hard to get + cash flow on paper.

Stabilization stage (you got your number of properties, or almost, but still need to make some tweaks to make sure you run your portfolio efficiently): You can pay some of your worse loans (high interest rates, ballon payments, etc.), but keep som cash is hand since you may need it for repairs, vacancies as you look for better tenants, etc. 3.

You can tweak your credit qualification criteria based on how you feel, as long as your process is fair to other applicants as well.

Most of the time I spend is "voluntary" - tweaking documents, researching re-fi options, talking with my contractors, etc.