For example, i'm making a game with a mine in it, and i want the mine too look good, something similar to this
https://www.scirra.com/store/royalty-free-game-tilemaps/cave-mine-tileset-172
I could just buy this but i want to make it on my own. As for the software im using, im using aesprite.
Yo! I don't know that software but essentially you want to create scalable tilesets (32x32, 64x64,128,128 for example) where the edges match up. I'd look for info with aesprite's community on doing your own tileset, as they'd likely have the best advice in using that software.