just use it normally in your article and don't go crazy. You can always go more generic off site

The term in specific is called Keyword Density. If you use different SEO Tool websites to check your pages strength, Keyword Density will usually be something that gets analyzed. You want to have your keywords/keyphrases in there, but you don't wanna overdue it. Having the right amount of density is where you need to be, and the only way to really do that is by checking it using one of the free online tools. Just Google something like "check my websites SEO strength" and you'll find dozens of free tools.

Don't try exact match domain, you can use other word at the end, for example your target keyword is "internet marketing" you can use internetmarketinganswers.com or internetmarketingsecret.com.

EMDs are fine. They just don't have the same benefit that they used to. You can of course use the same keywords, just don't spam with them.

If I had an EMD, I'd try to "brand" it. You know, use the name as a company name would be used. Would you mention your company in your content? Of course you would, but you would not try to fit it in every sentence.

You can still use it, just make sure that your anchor text are more diverse than a person with a pure branding url domain name.