If you want to make money you are going to have to write about stuff that people may want to buy, for instance if you write a recipe you can include a link to the cookware you used to create your culinary masterpiece.
If you write a book review then you can add an amazon link with related books or even unrelated books.
Now one thing that helps to get comments is to create a little controversy as folks always love to argue and express their opinions. One of the best ways is to create a title that will instantly create controversy.
However most people may click on your hub find it boring or too long, or just simple formatted in such a way that makes reading it difficult and only stay a short period of time.
The longer they stay on your hub the better as they may click on related ads and since most peoples attention span is that of a gnat, break up your hub into very small paragraphs, as I've done with this answer, it's easier to read.
Including polls and questions help and use many links. My two best articles in terms of money, readers and comments have been due to content, controversy and advertising of the hub.
So if you have a good one post a link on Yahoo News, facebook or twitter and any other social site you can think of.
However the best way is to learn from your mistakes, take suggestions and become the best writer and content formatter you can be.
Also if you read other peoples hubs and leave a comment most people will return the favor, unless your name is Justom or Watkins in which case your probable not doing yourself a favor.