Play in chain when putting tire back on

I ride a fixed gear, and occasionally after a tire or tube change (usually when I do it myself), I notice some play in the chain – a slight give in the pedals at a certain point in the cadence. I'm not sure how to get it just right. Too tight and it's bad for the chain. Too loose, and there's too much play. Are there any tips or tricks for getting the chain tension just right?