[cmiovino]

This might be the WRX owner in me (it's my current daily, and I've owned it 12+ years), but the general rule of thumb there was the check it at the gas station at each fill-up. That meant you were checking it every 200-300 miles and on a level surface.

You don't need to follow that exact procedure, but it's for people that don't have a garage or park on a level surface... or who just forget to check the oil. Doing it every fill up ensures it's never going to be catastrophically low. It's overkill, but that's the point.

Personally, I check my BRZ's probably every weekend or about every 100-200 miles in the garage. Also, put about 1/4" or so over the full mark so there's some leeway in there too. That way if it ever does burn any, you have a small reserve before it's even to the "full" mark.