I do it every few days depending on how much debris I've ridden through on my commutes.

To make it easy I hang my bike on the top rack of my bike hanger and use my phone flashlight to do a quick spin of each tire to see if there is any glass or other crap stuck in it.

I found apiece of brown glass (beer bottle) wedged in there a few weeks ago but not deep enough to puncture the tube. I dug it out and filled the hole with Silicon adhesive and all is well. I'm sure if I had ridden the next day with it, it would have worked its way to the tube.