The waders must be breathable. ...
The wader should be a stockingfoot wader, as they are more versatile than a bootfoot wader.
Waders should be as light as possible. ...
Unless you fish in near-freezing or sub-freezing weather frequently, there is no reason to get an insulated wader. Remember waders are not a fashion statement so allow plenty of room for movement and extra clothing in cold conditions. It is important to leave plenty of movement around the crutch area so you can negotiate river banks, fences etc without busting your seams. The most common area were waders fail is at the crutch and inner thigh, because they are to tight. You may look a bit like the Michelin man but trust me the fish won't care. Make sure your waders come with a wading belt and make sure you use it as it is an important safty feature. Also a good breathable material and welded seams are also important. Most good waders are made of a 3 layer breathable material similar to Gortex and have 4 to 5 layer for the leg area. This gives you added protection from wear. Gravel guards and hooks to attach to your boot are also necessary. Most brands make good waders and also have failures. So do your homework before you buy. Other considerations are pockets at least one waetrproof pocket for your camera and keys.
D rings are also usefull to clip on your accessories.
So you have a choice of full chest waders and when it's hot you can roll them down to your wading belt to keep cool. Trouser waders. Remember while trouser waders can be more comfortable they do limit the depth of water you can wade. Then you have your thigh waders which are popular when fly fishing small twig creeks in summer.
