As you stare at most years you start to remember ones you have seen when looking up ones you have in hand. It gets easier with time. The learning curve is more based on memories or how good any given persons memory is.
I found just looking up coins in a given year helped me out. Not that I had one, I still made and will make miss picks still. It's kind of like baseball it you never swing and miss at a pitch ....your not swinging the bat enough. In the last 4 days I bought a 1878 S with really bad photos and should have it later today or Sat. Looking at the coin and dancing with the photo to a Negative I will either have spent 18.00 to much for nothing or I will have an AU Long Nock. I also did the same thing with bad photos on an 1887 P that the date looked right and the reverse photo was so fuzzy that even playing with photo pro I have just a little idea. But I think I have about a 40% shot it's a Donkey Tail. The grade is right at MS-62 and that is as high as one would hope to find, and it looks to have some cracks in the right spots.
I find that asking for better photos on the Bay is like asking a blind man to See! I did ask on the 87 and the reply was that's the best I can do. If you what practice, find a few types that you like and just see if you can VAM
a few on E-Bay. Once in awhile you will run into a coin you find interesting and look it up and add more Info to your memory bank.
Never argue with an idiot..They will bring you down to their level, and beat you with Experience