A few people have released things on CS assets themselves, but not many people go full hog and make custom icons. I'll attach them at the end of this post, so you can jump to "keep reading" to see those. I even released a few.
The icon size is 20x20. You can use a bigger, square ratio canvas to draw on to make it easier if you're not doing a pixel icon. I usually go for 40x40 for more wiggle room if I'm not doing pixel art.
I apologize to the nice person who made a whole set of Pink & cyan icons, but you can recolor & make your own icons easily yourself too. It'll be more tedious than the premade set but you're paying for the convience & to support the artist with that one.
To recolor an icon, take a screenshot of an icon...
(my tools are a mess ;w;)
I'm choosing the default pens here.
Paste it to a 20 by 20 px canvas:
The background is the color of my tool sectioin so I know how it will look in it.
From here, I invert the layer using the CTRL + I (command on apple) shortcut. Then I adjust the brightness so the background is white & the icon is black.
Then I go [Edit] -> "Convert Brightness to Opacity" & bam, transparent icon. SAVE AS A TRANSPARENT PNG, then you're golden and can right click on a subtool/brush to replace the icon.
If you want each tool to show a different icon, right click on a tool and do this.
Or you can just put any square image in there like hank hill. Up to you. There's an archive of old windows 98 icons for things like scanning too.
Recommendations:
It's easiest to find them on the asset store under "image material" or "material catalog". Here's some cool ones:
A big Tool Icon
OSHARE's 200 types (super cute!)
OnyxChalchedony's pixel icons (always happy to see more pixels!)
Only OCD Friendly Icons 1 is free, but if you just post a color set on CSP for some clippy you can get enough for all within 2 days. Great for people who use a lot of decorations.
Icons for Special Rulers Set - I'm surprised these aren't default, they're very helpful for ruler users.
All of lee.norang's posts are nice and sleek icons to use.
These are for the command bar for grids & save types, which is one of the things I made for myself too. Love the colors on this one.
A bright set for bright cheery people
This one is in a layer template format, so you'll drag it onto the canvas and it will have layers come out. There's only a bit of JPN so if you can't read it, it isn't hard to modify or understand.
Two Packs of icons, big huge set.
BONUS:
You can print these out and use them, but you can also use them for regular icons. Very helpful!
There's more icons on CSP, but not all of them are useable across languages (i.e. I can't read Japanese so I can't use this Japanese character for an icon).
As I said earlier, I made some myself & will probably upload more of them I've made over the years for free since mine have no concrete theme. A variety pack of thift store leftovers type deal.
Ever wanted a bunch of stamps of Cambrian & Ediacaran Creatures? Check 'em out here! These are some of my favorite random brushes I've drawn, I love studying ancient life and it's fun to make weird things. :D
I recently got access to Photoshop, so I'll see if I can convert them to PS later. Sadly, they're only in Clip Studio Paint for now.
You can get them here. Even if you can't use clip studio paint, you can colorpick the image preview for any of them (take a screenshot then color pick if you can't download it).
Every 3-5 months or so I upload extra CSP brushes that are fun to use, but I don't want to sell since I don't think they're enough to charge for or are too experimental. Get 'em here.
