If you are trying to choose the best lounge chair cushions, you should consider first whether you will be using the chair indoors or outdoors. The cushions you choose for indoor lounge chair use will likely differ greatly from the cushions you might select if you're planning to use the chair outside. In general, lounge chair cushions for outdoor loungers need to be waterproof with flow-through fabrics and colors that aren't likely to fade in direct sunlight. If you are using the chair indoors, you won't have to worry about these requirements, and you can instead select good-quality cushions that are comfortable in the colors and patterns that you prefer.
Many people associate lounge chair cushions with outdoor use because most indoor loungers come with cushions attached. Outdoor loungers usually have removable cushions so that they can be easily cleaned and replaced when needed. If you are using your lounge chair outside, it's probably not a good idea to buy cushions made for use indoors. Using any type of furniture outside means exposure to the elements, and rain, sun, and wind damage are all likely to occur over time. Most lawn and garden centers carry large varieties of different lounge chair cushions for outdoor use that should meet your needs perfectly.
Using a lounge chair inside means that you aren't quite as limited when it comes to selecting cushions for your chair. You don't have to worry about weather exposure, so you can pick out any type of fabric in whatever color you prefer for your lounge chair. Before purchasing the cushions, you should probably try them out in the store to make sure that they are comfortable to sit on. If you're ordering your cushions online, you might want to find out what the return policy is for the particular store you are considering in case you receive the cushions and they are not to your liking.
The prices for both indoor and outdoor lounge chair cushions tends to vary. Purchasing extremely cheap cushions might save you money, but if the cheaper cushions are of poor quality, there is a good chance you'll be replacing them within a few years. It's also occasionally true that the very expensive cushions are not quite as high quality as they are advertised to be. It might benefit you to do your homework before buying lounge chair cushions so you can be sure that the cushions you select will last a long time regardless of how much you pay.