writing for MNS

Are there any special tips or tricks SEO wise when writing text for Micro Niche sites, or is it just a fact of having well written articles?

I dont think google looks at different niches. It works the same algo regardless of what content it indexes barring the exception of adult and similar niches.

So I wouldn't change my writing in any way.

What i ment is ive never written anything for a website before, is there anything special to keep in mind when writing for my sites, or is it just about having a well written site?

Either learn LSI or do as most do, and keyword stuff your articles.

Get your main keyword in the title, H1 and opening paragraph.
Get your main related keywords in the opening paragraph.

Dont over keyword stuff the article, try and use lots of related keywords, plurals etc instead.

As far as keyword stuffing, I would avoid it. I've had my best success from 1-2% keyword density. Even 2% seems spammy for a lot of keywords, especially for 3+ word ones.

It's also very useful to leave the user wanting more info. If you've covered your topic perfectly there is no reason for them to click an ad. My terribly written articles seem to do much better in terms of CTR on ads. This fact does bug me, but that's the way it is.

If you're writing in Wordpress, get a plugin that shows your keyword density.

Be sure to cover your tags. H1, h2, h3, etc. Don't feel the need to stuff the keyword into every tag. The page title will be enough, and most like to get it into the h1 tag, too.

Longer articles seem to do much better than shorter ones, 900+ word articles are working for me.

This is more niche/topic related, but "buyer" related keywords/articles get a vastly higher CTR on ads. An article focused on "Dog collars for $5" will do much better than "How to tighten a dog collar." This is obvious stuff, but many people wonder why they have such a low CTR - this is usually the biggest reason.

As someone else mentioned, you could look into LSI keywords. These help make the article look more natural, as a naturally written article will usually have many in it anyway.