I set up virtual accounts for each property that is linked to my main operating account.

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. 

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.

An LLC is a smart move for individuals looking to protect themselves, grow their business in a professional light, and operate as a corporation. 

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.

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.

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. 

A previous Client and employer of mine came to me wanting to unload a property.

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.