House Doctor Ray has some fantastic ideas for improving the performance of wet/dry shop vacs.
The first “hack” to use a pool filter sock over the vacuum filter to make it last longer and be much easier to clean.
The second is to add a homemade PVC muffler to the air output to quiet the vacuum down (mine sounds like a 747 taking off).
The third is adding a Dustopper dust separating accessory. This latter improvement you only need to do if you’re a woodworker or otherwise generating lots of material like sawdust.