Searching For Errors

so I'm going through a box of pennies right now and have a box of halves on the way to my bank (Go Bank of America!). I usually look at every coin under my loupe and just scan it. I have a list of dates and things to look for with pennies and use that quite often, but I don't know anything about half dollar errors/ varieties. I know there are quite a few minor doubled dies to look for, but not sure how to go about this. should I look at every coin up and down or is there a faster and better way?
(not sure if this would be better off in the coin roll hunting forum, so move it if needed)