$800,000 to invest? How to start building a single family portfolio

If you had $300,000 in cash and around $500,000 in equity on some properties how would you go about building a single family rental portfolio? I know there is an argument to go commercial over single family but the properties owned already have been great with zero problems. Whats the best way to go about financing and a comfortable leverage ratio for the portfolio. I intend for this to be a long term investment strategy and try to acquire multiple properties a year.