How to Make a Beanpod
If you're making your own bag, first cut the cloth so that when it's folded and filled, it will create the shape of bag you'd like. Then sew along the edge until all but a small hole is sewn up. Then turn the bag inside out through the hole. Quick and easy bag!
Depending on the make of the bag, you need to somehow open up a small hole in it through which you can pour the filling. This could be as simple as unzipping or undoing a flap. The smaller the hole, the less work you'll have to do later.
Pour in enough of the filling so that, when closed, the bag is mostly full but so you can still change the shape of the bag somewhat.
Close up any openings to the bag. If the bag has a zipper, you can use strong thread to tie them together. Otherwise, sew over the hole(s) until the seam does not give at all when tugged upon. If any leaks ever form during the use of this bag, then it's very easy to fix: just sew over it again, making sure to overlap with stronger sections of the seam.
Creating straps, if the bag does not already have any, may make using the bag easier. Simply cut strips of cloth to whatever length and width you'd like your straps at, then sew them onto the bag, making sure to sew over the seam multiple times for greater strength.
If you feel like making your beanbag a bit prettier, there are a number of things you can do. The material of the bag itself is the first consideration, so make sure it's a pattern and color you enjoy. Otherwise, you're only restricted by your own creativity: colorful scrap patches, paint, beads, anything you can think of. Just make sure that whatever you add onto your bag won't accidentally damage the camera.