Most of the time:

JPEGS: Save for Web qual 100 > JPEG Mini > ImageOptim

PNGS: Save for Web > Image Alpha > ImageOptim

On the stuff that I really need to squeeze every last byte out of, I save PNGs so I have a lossless file to fall back to, then use ImageMagick to compress to taste:

convert -strip -interlace Plane -sampling-factor 4:2:0 -define jpeg:dct-method=float -quality 85% source.png result.jpg

I just tweak that quality number until it looks as crappy as I can deal with.

Notably, I change the sampling factor to dump the chroma resolution, which is harder to notice. Saves loads of space and is very hard to notice with retina assets. I also use a more power-intensive calculation method that usually looks a little better, lose the -define jpeg:dct-method=float bit for more speed.

Hi Michael, I still use PS save for web, but I also run jpgs through https://imageoptim.com/mac

and my PNGs i run through https://tinypng.com/

Even after save for web, tiny png especially reduces images by a further 50% or so.

Manually. My Photoshop keyboard short-cut game is on point.

I normally export images at maximum quality at 1x and 2x in Photoshop with a plugin I created (freely available here), optimize them in visually lossless mode with an image optimizer I'm currently working on, and use the srcset method with a simple JS fallback I wrote a while back.

It depends on the setup. Are you building a static site or using a CMS?

A CMS can often dictate this, and with WordPress for example, srcset coupled with a resize/compression function becomes the default option. It works well, and can handle almost anything a client throws at it.

PS Save for Web 90% > ImageOptim.

https://imageoptim.com/mac

PS Save for web. When I read the title the first time I thought it had something to do with this wonderful blog: http://saveforwebclaws.tumblr.com/

For pictures/photos, I resize the images for 2x and use Pixelmator on the Mac and export for web. I usually set my JPEGs at 60%-80% quality. For a 1600x1000 image, it ends up being around 100KB (sometimes less). I just do this by eye, and as soon as I see a degradation in quality I stop. For thumbnails, I tend to go slightly lower quality. I find that 40% is still more than usable. I then use JPEGmini, just to squeeze any more optimization from the image as I can. For me, I want my pages to load as quickly as possible while still ensuring that the images look good.

I don't use many photos, but all my image assets get ran through Kraken for compression.

I haven't found anything better for lossless size reduction.

Hey Michael - still mostly saving as jpgs (save for web from photoshop) and then compressed with a tool such as tinypng or something similar. Usually gets the image size into the low kbs and retains enough quality.