Sometimes during development I see that the instance of sqlservr.exe is using > 500MB of memory. When this happens, performance for the rest of the apps running on my machine take a hit...so I needed a way to control how much memory sql server consumed. Turned out to be very easy:
1) Open SQL Server Management Studio, right click the server instance in object explorer:
2) Click on 'Memory' and change the min/max memory usage to your liking.