After three weeks of diligent searching and some expert advise from this community, I have learned more than I expected in such a short time. So getting back into it will be easy for you. Post any pictures of coins your not sure about and an expert will let you know what ya got.
In three weeks I have gone through about 2000 pennies, the most common I find are the weak MAD cents, the devices are usually still on the coin so they are not worth much to collectors but I keep the ones I find. I found one clash that was a great find for me and one of my best finds so far, other than the 1939D nickel. I have found a few rim
Cuds, die gouging, die cracks and chips. When I am searching through coins, I am looking for everything and separate coins that need closer attention into their own coin envelopes for further inspection at a later time, for example: small dates. I keep a cheat sheet in front of me and glance over each coin first looking for obvious errors or varieties and comparing the coin to my cheat sheet so I do not overlook a known error by mistake. After a few hours of that, you will start to memorize key dates and sought after errors like the doubled dies, CAMs and WAMs.
The hardest part for me is learning all the different doubling that can happen to a coin, some of it is collectable and some is not, research this topic well.
It is so much fun getting back into this, I have so much to learn yet.