Best practice to get high ranking for specific keyword?

The most important point is to add your keywords in your content & be careful about keyword density & keyword relevance.All of the methods you've added here could be failed without these two points.So it's more important than any other methods.

 

Changing conten? What do you mean?

 

Updating your blog regularly is the best practice to get high page rank.

 

This only give you traffic not Page Rank. Page Rank relies on quality backlinks.

 

Use the keyword inside your content but never spam the keyword

 

In addition to that, if you spam it, you will induce keyword stuffing.