Also do webp conversion as basically last step (I do it before I start tagging, so tagging tool is working with smaller file sizes). Wanted to add something I started doing recently, as well. There is a bulk image resizer you can find online (bulkresizephotos).
In the interest of keeping overall pack file size as small as possible, and because the game doesn't display above like ~1300 IIRC, I grab anything showing more than ~3mb file size, and bulk resize it to be "longest side: 1300". Keeps the aspect ratio the same, so you won't get any stretching/warping, but cuts the file size down considerably (you can also choose to output as JPG, which should be smaller than PNGs, so that helps a bit while you are working through the files before you convert to webp down the line).
In the interest of keeping overall pack file size as small as possible, and because the game doesn't display above like ~1300 IIRC, I grab anything showing more than ~3mb file size, and bulk resize it to be "longest side: 1300". Keeps the aspect ratio the same, so you won't get any stretching/warping, but cuts the file size down considerably (you can also choose to output as JPG, which should be smaller than PNGs, so that helps a bit while you are working through the files before you convert to webp down the line).