In terms of making it a truly different planet, you could add unique plantlife or other structures in the background or recolor the sky using EbSynth. A green sky would be interesting. Especially against purple sand. However, I feel like the sand would be an absolute nightmare to recolor. At most, you could maybe tweak the color balance slightly, but that’s it.
Oh and I’ve said it before and I’ll say it again: make Ilum (Starkiller Base) a snowy volcano. It’s an idea that appeared in concept art and would help resolve the issue of the fissure that splits Rey and Kylo once you remove the “destroy the superweapon” part of the film. Just add lava flowing to some of the wide shots and voila!
Yeah the Art of TFA is very inspiring, pitty they didn’t incorporate a lot of the unique stuff in there. As for Jakku I think sprinkling crashed Star destroyers/Mon Calla cruisers etc wherever possible would give it a look that is more distinct and evocative.