I'm making sure I don't scan anything in a sleeve (the few that were originally in sleeves I've taken out before scanning), scanning at 400 dpi, straightening and cropping as needed before submitting. Many have been flagged as "not cropped", too, but I've been just putting up sith it and using the crop option below the graphic to just barely take the edge all the way around and every one of them has been taken on the re-submit. I get a little frustrated when things get rejected for a reason I don't understand. I want to be able to fix my own mistakes when it's an error on my end. It's my responsibility to do it correctly, not someone else's to clean up after me.
That said, I do appreciate having someone review my scans before they go in the database. Mistakes do happen, especially since I'm spending many hours a day sorting and entering what I have. My stuff has just been sitting, much of it not even grouped by sport or set, in card boxes and holders in the garage since 1993 and I had no idea about a lot of what was in there.
I'm definitely not looking forward to building my memorabilia database but that can wait until I'm done with a few other projects (stamps and family photos). I have 4 decent sized totes full of hats, souvenirs, programs, autographed minor league balls and other collectibles from many sports and non-sports.