I trained a Hardy Boys Casefiles Krea 2 LoRA that turned out well and someone suggested Goosebumps. I found all 62 covers from the original series, all 1280px wide, with heights ranging from 1803 to 1859. On the Hardy Boys LoRA, I resized by height to 768px and padded to 512 width basically with 10-20px black bars. Those black side borders can come through in some generations. With these Goosebumps covers I resized all to 512px wide keeping aspect ratio so the heights ranged from 721 to 744.

I did this training twice, tightening up the captions the second run for better prompting control over the color and texture of the Goosebumps logo and the background color. And almost always concluded with "Scholastic logo lower left."

I also included a .txt file with all the captions used in the training.