There are an awful lot of things to consider when you're writing a TechNet Wiki article. Some of these are more important than others – here's a list of the things you REALLY want to (and must) do right .
It's a Microsoft Wiki and to be appropriate your article must be directly related to some Microsoft technology. Keep the language professional. Keep the content professional – harmful scripts are not acceptable. If you recommend something which is widely considered bad practice then make it very clear what best practice is and what special circumstance justifies your approach.
If there is already a TNWiki article covering your subject then you should edit and expand on that, rather than writing a new one.
Unfortunately, some people post direct copies of someone else's content. Not only do you not want to do that, you also don't want to find your article turns out to be remarkably similar to one already published elsewhere.
Looking like you copied someone else's content is effectively just as bad as copying it.
Get Your Facts Right
If you're showing pieces of code then people are likely to try them.
Make sure they work.
When you describe code or pictures then make sure your words match the pictures.
Carefully read any documentation. Particularly if you post a link. You definitely don't want to find your article is contradicted by one of the links in it.
Test any assumptions.
Writing a TechNet Gallery sample which goes with your article is particularly useful in that you can be confident what you're saying works definitely does.
You can easily find something you learnt 5 years back has since changed. That happened as I wrote the samples for several articles.
Conform to the Standard Format
There's an expected format with h1 and h2 heading tags, and a TOC. Take a look at a few other articles if you find the documentation a bit dry. You're also expected to use third person rather than "I".
As the original author you get your Kudos from being listed as the original author rather than by listing all the things make you great. Remember that this is a Wiki and by definition everyone is expected to be able to edit any article.
Any CSS has to be inline on a tag and the current platform cannot cope with fancy html so keep it simple. Use named colours rather than hex, RGB or any other color code numbers.
When you have time, read through the article linked articles in the Governance and Guidelines Portal.