Wedges help you sit better and help prevent slouching. The Gymnic Movin’ is my favorite wedge. It is inflatable so you can vary its height and density. And because it is inflatable it moves with you so that you are not sitting stock-still. They even make one for kids so that the youngsters get a head start at sitting well. Another good wedge is the Desk Jockey. I like this one because it is firm. You want the wedge to be firm not soft.
You do not need to spend hundreds or even thousands of dollars on an ergonomic chair. A firm kitchen chair will do the trick such as the Flash Furniture Hercules wooden restaurant chair.
A good yoga mat is perfect for your lie- downs. I prefer the Gaiam Print Premium Reversible Yoga Mats. I like its thickness and I love the colors!