good start but they are a bit square. you need some end pieces to round them off and make them look more irregular same with the bottoms if you can see the bottom of the platform dangling in the air, you may want to do something of a bottom pieces to keep it from looking like a flat box
I always recommend people to make fake screenshots of the tileset. That way they can see if there's any ugliness or in my tileset's case... mismatching lines: