Combine equal tiles (models/ sprites) into bigger ones, f.i. 2x1 tiles, 2x2 tiles or even bigger ones. When you want to remove a tile (by digging), delete the big tile and recreate 2 or 4 tiles respectively. I've used this method in 3D with models (see Projects: MeinKraft) and 2D with panels.
"Falls das Resultat nicht einfach nur dermassen gut aussieht, sollten Sie nochmal von vorn anfangen..." - Manual
