It really depends on your investment goals. There is no universal answer. I'd recommend that you spend some time talking with an agent (myself or another) that specializes in working with investors. I'd recommend looking for a firm that offers a turn-key approach, including finding the home, leasing it out, and managing it. Many agents say that they 'specialize' in investment properties, but they also specialize in waterfront, luxury, first-time buyers, etc. Agents that claim they specialize in every type of brokerage always give me a chuckle.
I dislike generalities, but here's what I will suggest, broad strokes, without knowing your investment goals. Look for homes in the $175-$225k price range, in S/SW Austin, NW Austin, or parts of Cedar Park and RR. Those homes will give you a good blend of rentability, positive ROI, and strong appreciation potential.
Don't chase cash flow. The wins in rental property come long-term, from minimizing turn-overs and having high-quality tenants. A brand-new house in Hutto or Buda may look appealing on a spreadsheet, but won't pan out that way.