Here are some guidelines that you should try to follow while preparing content for credible-content.com as well as http://contentgyan.com.
Most of the article titles are going to contain two keywords or key phrases, for instance “Content writing services for real estate business”; in this case the two keywords are “content writing services” and “real estate business”.
Try to use both the keywords in the first and second sentences of the first paragraph, then 4-5 times in the main body and then once in the last paragraph.
Use at least three headlines while arranging your content (for reference you can go through a few block posts on http://contentgyan.com) and at least in one headline use one of the keywords and in another, the other keyword.
Use at least one bulleted list and use both the keywords at least once in the bulleted list (I don’t mean in every bullet).
Maintain a standard, don’t try to do a patch of job because then your article or blog post won’t be published. Again, go through as much content as possible on this website to get the hang of what sort of content I have been publishing so far.