Cover the basics. A shooting vest shouldn't be bulky and impede your movement. It should give you plenty of storage for your shells and safety equipment, a nice recoil pad, and keep you cool when it's hot out. The Trapper Creek mesh shooting vest has you covered on all these points and more. 

4 oz. cotton twill fabric with 100% polyester mesh body for ventilation
Full-length shooting patch with sewn-in REACTAR G3 pad pocket (pad sold separately on pg.53)
Four shell pockets
Side webbing adjustments
Large rear hull pocket

Warning: Cancer and reproductive harm: https://www.p65warnings.ca.gov/