For my first BP I had a sweet setup. Fake rocks with built in hide, fake plants, blah, blah. But then came the 2nd snake, then the 3rd, 4th, 5th. With this comes more poop and tons of stuff to scrub/disinfect. Currently all five of my snakes are in RBI cages with 2 simple hides each, a water bowl, a big rock for shed assistance, and brown painters paper as substrate.
Not to minimize the importance or want to decorate but if you want to keep a pretty/display enclosure, don't get more than one snake.
That said I enjoy seeing setups so post away. About bark or shavings, I always hated seeing my snake with a shaving stuck in his/her mouth or on a tooth so I opted to use the plain brown painters paper sold as a 500' roll at most major hardware stores for approx $5-$10. It will last years with only one snake.