Here some my maps for Portal 2 from steam workshop:
https://steamcommunity.com/id/BansheeRU/myworkshopfiles/
These maps hasn`t special graphics and not too big, but they hard to solve (because steam workshop hasn`t big amount of this). And it really hard and interesting to create this puzzles. It`s examples how create hard puzzle with few elements only.
BBE-mod used for adding some elements not included in in-game editor.
Portal 2 - CUBESTx01walkthrough
Portal 2 - CUBESTx02 walkthrough