I often get people asking me about what investment strategy they should implement, but the answer is always the same. Investing in real estate is a personal endeavor. You have your own unique skills abilities and you should develop your own investment goals and strategy. You should realize that you are not going to be investing, you are an entrepreneur and you will be building an investment business.  

You're providing a product (housing) and service (management) to customers (tenants).  You must continually strive to create value for them and therapy compete with other investors providing rentals.  So focus on providing the ideal product and service for their needs. Focus on providing value.  This applies to all aspects of your business. The quality of people that work with you, how to treat your customers (tenants), structure of your leases, quality of your product, etc...there is a lot more, but this should help get you started.

This framework (below) will help you develope your strategy:

This graphic is from Gary Eldred's "Make Money with Small Income Properties".  If you've not read it, I highly suggest doing so in addition to all other books by Dr. Gary Eldred.  He's a pro and used to teach at Standford University.