custom textures : Not many people think about them when building let alone want to, yet they allow the most creative designs and even colors, they are useful for all realms, shops adventures parkours games calna dn whatnot and best of all : they're cheap and craftable!
I recommend keeping a stock of shops and places that sell textures, so when you're struggling while looking for a design, you can check those out and see if there's anything that fits your taste.