Check out the above video wherein Photoshop Principal Product Manager Bryan O’Neil Hughes shows us how to use filters in Photoshop (and which not to use). He covers the older Filter Gallery and using it with blend modes for creative effects.
Additionally, he shows the benefits of using Guassian Blur on a layer mask, along with the new Blur Gallery in Creative Cloud versions. There are several more in the short 7-minute video with which you may not be familiar.