Where possible, it’s best to try automating image optimization so that it’s a first-class citizen in your build chain. To help, I thought I’d share some of the tools I use for this.
Not only contains a list of grunt plugins one can use, but also a few command line and online tools. I’ve been using TinyPNG for quite some time now before uploading images to my blog. Can shave up to 83% (!) of a screenshot created in OS X.