Consistens is a must.
Low quality or unreadable content should be avoided
Don't put too much ads
Internal linking is a must, if its relevant
Don't add random articles about a total different topic. If your blog is about the travel niche, don't write about video games or the stock market
Try to interact with your audience
Make everything look natural as possible
Don't make the blog look too spammy. Means don't put too many links, not too many pictures, sidebar should be clean, design should be clean, no aggressive colors. Sometimes less is more.