I think my favorite part of the forum and the dominionstrategy site is probably the articles. I've learned a lot of tricks from them and still feel like there's a ton to learn.
That said, I think the quality of the articles could be much better if people only followed a few simple suggestions. Feel free to disagree...but I think a lot of these are intuitive enough and certainly feel like a good idea to me.
1. Back up your claims.
A lot of threads about strategy are filled with one-off comments asserting something. Sometimes these are refuted by other people. I have no real way of figuring out how might be right.
Articles should provide a deeper look and more reasoning. So take a hard look at your assumptions and try to give me some evidence to back up what you're saying. At the very least, show me your logic.
Maybe the biggest point here is, if you're not high-level, your personal experience may not provide a good guide, so look to comments from more advanced players to check it. (This clause applies to me, BTW.)
But more to the point....
2. Do a draft, and maybe even two or more, before publishing an "article"
This is all toward improving the quality of your advice. And one of the best ways to do that is to subject it to public scrutiny.
I noticed a recent article on Remake was titled "Remake (draft)" That's great (and follows a precedent I think I might have set myself...) because it lets us know that you're (hopefully?) going to go back, look at all the criticism and then incorporate back into a new version of the article, so that each future individual reader doesn't have to go back and read the entire thread to pick out the useful from the inane, etc. That just helps us, as a community, avoid duplication of effort.
3. Read previous threads on the same subject and try to take the best advice from there.
'Nuff said.
4. Break your paragraphs up and give them subheadings.
Personally, I find it hard to read long paragraphs on a computer screen, so this is nice in general for anything that isn't supposed to be a narrative.
But this goes doubly true for advice like this. Remember, as a player I'm going to have to integrate your advice into a complex web of knowledge I already have in place in whatever implicit decision tree I'm already using. It's a lot easier if your advice is broken into discreet chunks. (It also makes it easier for people to critique.) And using bold for these subheaders is always welcome.
Here are some good ideas for subsections for articles about single cards that you might include when appropriate (thanks to GendoIkari for this list):
Lists of cards/types of games that the card does and doesn't work with.
Comparisons to other cards.
Common traps/pitfalls that people fall for with the card.
Example games.
Statistics (when councilroom is up)
...That's it. Happy writing.