I use paper and toilet paper rolls for all my snakes, they love them. I also use shake n bake boxes lol. For those of us who have only a couple of snakes it's pretty cheap to decorate a tank.
Cheapo stores are the way to go. Or craft it such as vines and such. Just get a rope roll it in silicon and dip in coco husk and tada you have a natural looking vine. I love the crafty things :)
I have fake plants and drift wood in my tank and I use that bark stuff for the bedding. Cleaning day is tomorrow so I am switching to the coco blocks. I myself like the natural look. Well except for the boxes :)
If it won't harm your snake I say decorate however you like! I don't think it's a waste of money at all.