Need advice on creative rental income

[Josh Pryor]

So, I bought a house at a reasonable price of 60k and lived in it for a year. I then promoted at the company I work for and relocated several hundred miles away. I am now using my property as the first of (hopefully) many other rentals. My question is this, how can I make it a little more profitable to be able to save enough for more properties? I have an interest rate of 4.25% and I have only had it for 4 years, so I feel as though refinancing isn’t a great option. My mortgage, insurance, etc, is $507 a month. I rent it for $650 currently. I’m looking for creative solutions you may have had. Please help!