This is a good read. just to get a sense of some of the OSS maintainer experience. As far as a practical guide, it's my experience that the vast majority of users of OSS software libraries "get" these things already and therefore you don't hear from them. However, just 1% of users who don't "get" it at all, and do all the direct messaging / manipulative stuff are still there, and that's who ruins your day.
Which then leads to, those people are absolutely not going to read a blog post like this, they can't even read GIANT LETTERS IN BOLDFACE at the top of a github template telling them to please provide a test case / stack trace / etc.
After doing this for 16 years I have realized that while you need to put up guidelines, instructions for interacting, issue templates, etc., at some point you can't keep putting up signs to PLEASE DONT DO THIS - because the people for whom the ALL CAPS is intended for are the last people to read/ care about any of this, and the stern messaging otherwise brings the mood down for that vast majority of users who aren't going to be bothersome in any case.
You have to just have a pre-packaged response for the various things you get:
1. "hi" on IRC in private message from someone you don't know (obviously looking for help) - ignore. there's no response you can have for this person in this setting that will make the situation better (keep in mind, there are many forums / chats/ systems this person can use to get help, and they are well documented. these people ignored all that and are trying to go right to the main dev to get private help. they most certainly know how to find things because they found your nickname on an irc network. so this is overall a pretty rude move, but even then, some people just arent aware of what they're doing or how to act)
2. email asking for help - this is probably not too different from the "hi" in private message thing but I tend to give folks like this a short answer and point them to github discussions / irc, mentioning "there's some folks there who can help us further" (note the word "us", to soften the blow a bit). the emailers tend to be completely bewildered and generally lean heavily towards overall beginner types so I do try to gently guide them into the wider community for help.
3. recruiters - geezus, they just don't stop. I pretty much ignore them, which they have all caught onto these days so they email you over and over again...I will send back a one liner about 50% of the time after they've pinged me three times
4. weird link-sharing emails who want to put some kind of endorsement for some programming tool on my site that makes absolutely no sense to be in the context they are proposing - I usually just ignore these. Hard to tell if those are spam robots or what but they can be persistent with fairly emotionally charged "can you at least tell me what you'd be interested in?" kinds of replies...I mean these folks I'm sure are sending thousands of these emails out, are they sending out hundreds of frustrated third-requests to everyone who doesn't reply also?
I do feel for this developer since producing a JS web-development oriented library is going to generate lots more attention from a lot of users with relatively low levels of technical sophistication. I'm thankful that the Python world still attracts high quality people with reasonably good manners about things.