Trained on 200 images of pixel art scenery. I've only tested it on the AnyLoRA checkpoint and i would recommend using it. Use a weight around 0.7 and a CFG Scale of 7 for best results.
I usually generate an image at 768x512 (or 768x432 for a 16:9 image) and use hires fix at 0.5 denoise, 10 steps and with the R-ESRGAN 4x+ Anime6B upscaler. In addition to that I use the PXL8 extension to downscale the image and reduce the color palette. If I am generating a 768x512 image with hires fix i usually downscale it by 4x to end up with a 384x256 image, I usually put the color palette size at 64. Right now it struggles with character, sometimes it works if they are further away.
I would recommend using "scenery, fantasy" mainly. Otherwise just look around on danbooru or other booru sites for tags, some nice ones are "dappled sunlight", "mountainous horizon", "overgrown" etc.