Yeah i used to dress pastel goth a bit when i was younger and the easiest way to do it is picking a pastel main peice (dress, sweater, skirt, etc) and then black everything else. Shoes can go either black or pastel, but black would probably be easier to find. Platform shoes like creepers generally work best. and then also get a bunch of pastel accesories on top like the lil crosses, drippy pattered stuff, bats and aliens and stuff. Its a very cute and comfy style so have fun!