This is a short instructional guide on how to terraform. For this guide to be of any use, you need WorldPainter. It's an easy-to-install external program. I also recommend you have WorldEdit, Voxelsniper, and/or MCEdit. Play around with WorldPainter a bit. You can create really amazing stuff that way. Some tips: Mess around with hill size and water level. The surface layer doesn't have to be grass. Don't screw around with water. Add a little something extra. I hope this helped!