financially support Krita: either by donation, buying something from the store (like Digital Atelier bundle), or buying Krita on Windows Store or Steam or buying the “Supporter’s Badge” on Play Store.
the most useful and also the easiest to get into is… helping other users. There is plenty of help requests every day for example on reddit (r/krita). They are here on KA too. A bit of patience and knowledge about Krita can go a long way. Some time ago I was able to handle them all; but right now, it’s just waaaaay too big, even when @Rakurri and @Rebecca (…I hope I tagged the correct Rebecca ), LainFenrir and other people help me there a lot.
I cannot really help there anymore, but I’m always really sad seeing all the questions being unanswered.
I think it’s just about all… in any case, I’d really appreciate more people involved in user support. Here I can see that most posts are answered; but on reddit right now, most are not answered for a long time, sometimes never. If those are about technical issues, it might be the difference between them being able to use Krita or having to give up on it and look for something else.
Other than that, I have a specific task that would improve user support: https://phabricator.kde.org/T11427 - I’ve made it to keep track of all the things I wanted to add but… I just have no time to do it now, especially think through etc., but maybe something from there would interest you.
There are of course sections “Introduction to Krita from X” where X is another art program; but that require a knowledge of another art program, of course.
Also btw, bug triaging is not the same as bug reporting: bug triaging happens after someone reports a bug. It’s basically opening the bug report and checking what’s inside, is the bug valid, can I reproduce/repeat the issue, shouldn’t the reporter go to the user support forum like KA first, etc. It’s not exactly a non-technical work, but it’s easier than coding; often you just need to try to replicate the problem or ask the user for more data if you cannot replicate. Then you need to change the status of the bug appropriately. There is a Manual page that explains it: https://docs.krita.org/en/untranslatable_pages/triaging_bugs.html
An quick easy and non destructive solution is just to add a new empty layer on top of the layer to edit and put it to “copy to {color}” then paint white to add some of this channel or black to diminish it and finally transparent to be neutral.