When funding is rare and flips are plentiful, there will be enough opportunities for everyone but return will be depressed and better operators will make better returns. 

Use an operating account for income and expenses, a reserve account for maintenance and taxes, and a high-yield savings account (HYSA) like Capital One's 4% APY for idle funds awaiting reinvestment.

If you materially participate in the LLC’s operations, you may be able to treat the income as active.Material participation in a rental activity, with or without an LLC, still runs into PAL rules.

One thing I would mention though - doing STR just to save taxes often leaves you operationally unstable or too detached from the management to be successful.

Quote from @Carlos Lopes: Gross income doesn't matter.This is the number most people post, and it's 92.7% useless.What you need is NET income, meaning the money left over after all expenses, and that should include a dollar amount for your personal time spent operating the business. 

Also, depending on your long term goals, transitioning part of your portfolio into more passive investments might help reduce operational stress while keeping your equity working for you.

Simply document everything you do and create your own Standard Operating Procedures (SOPs).

., appliances, fixtures, landscaping) into shorter depreciation categories (5, 7, or 15 years) rather than the standard 27.5 or 39 years for real estate.2.

What tools have worked best for you to streamline operations? 

A lot of investors have great success when they start with a deal that has lighter value-add potential and use that deal to learn how to operate a rehab.