If you cant come up with original ideas, you can always try to remodel puzzles by other authors.
Often something totally different will be the result.
Title: Working Out Rev
Author: Chaib + Tyge Fogh
Comment: Original level found at Game-Sokoban.com. A slight revision is pushing up the difficulty. First at SokobanOnline.
You can download the collection Remodels1 with the puzzle above and a few other remodels here: