If the bag came with straps, either separately or attached near the head, it is likely meant to be rolled. These straps are meant to keep the bag rolled up. If you need to save space, rolling your bag is the best way to compress it into its smallest shape. However, you should try to remove your bag from compression as soon as possible. [1] X Research source
If you don’t have straps, you can improvise one out of a belt, large rubber bands, or rope. If your bag came with a bag but no straps, store the sleeping bag in the appropriate carrying bag and close the top tightly.
Loosely roll your bag, or let it rest, lightly folded, when it is not in use.
Always start packing by the tail if you use a stuff sack – this allows the air in the bag to escape through the top.
UV light can damage the sleeping bag fibers, so take care not to leave the bag in the sun all day. [8] X Research source