First off, to write a guide, one must have a subject. Case in point: guides.

After choosing your subject, you must re-evaluate how well you know this subject. Can you explain it? Do you understand it? Can you simplify it?

If not, then choose something else. Try an action, like picking out paint colors or deciding which pencil to use. If so, then continue.

You now have your subject: what you're writing a guide to. I advise you to use bullet points to explain how you do this thing. Now you need to generalize it (if your guide is for the public), or specify it to cater to who this guide is for. A guide to fungi for children will need pictures and simple words, whereas an anatomy guide for medical students will need to be applicable to their studies. It will need a level of complexity. Evaluate your audience, adjust your steps accordingly.

Sometimes, it would be beneficial to add an introduction. A precursor to what your guide is about, or an elongated summary of what comes below. Case in point: the above.

In short, to write a guide, one must

1) find something to write a guide about

2) ensure understanding of this topic

3) briefly list how it should be done

4) change wording, visuals, or format according to your intended audience

And finally,

5) add an introduction, summary, or conclusion if deemed necessary for comprehension.

Should you find yourself struggling, I suggest having many strangers (if your guide is geared towards the public) or members of your intended audience, read over your guide. Take their critique, and re-evaluate step number four for further improvement.

At the end of all this, all you must do is ensure that your audience receives your guide. You might consider printing and posting on a public board, publishing to a website, homepage, or social media site.

I hope this guide finds you well, whoever is reading, and that it should help you in your further guide-writing endeavors!