Not a duplicate of What software is available for map creation? as the focus is on how, not what -- requesting useful projections for a polar context, and techniques to transform between projections to achieve this.
I've created a simple earthlike planet for a Dnd campaign I'm running, and I wanted to minimize inhabited areas to keep things simple, so I put my continental plates on the poles. I also liked this idea since a lot of fantasy maps seem to completely avoid putting continents in areas where they are more distorted by map projections. However, I'm beginning to realize why. It doesn't look good projected with north at the top and south at the bottom because everything's totally warped. I want to re-project a rectangular map with the equator at the top and bottom so I can get a clear look at my continents. I can't figure out how to do this— I've got gplates, g.projector, and photoshop but nothing seems to rotate a raster on a globe. UV unwrapping in photoshop might be my best bet at this point, if anyone knows anything about that.