You can make money using video sharing sites.
You can create blog on Blogger or Tumblr and advertise it on plus.google.com, Twitter or Facebook.
You can use the keyword tool in AdWords to find a key phase with less competition and high amount of monthly searches and create blog or site with this key phase, but when you use the AdWords keyword tool don't forget to uncheck "Broad" and check "[Exact]." Optimize your site or blog with good title (every page in your site must have different title), good content, <h1>..., it will be nice if your URLs contain the keywords for the corresponding page... Avoid duplicate content, when you write text don't use the keyword too often (it's not OK in text with 70 words to use the keyword or key phase 15 times - this is too much). To receive traffic (visitors) to your site or blog from the search engines like Google you will need to make link building for your site (to create links in other sites pointing to your site). When you make link building don't create too many links at once! If you use AdSense read the rules and don't violate them, because if they ban you you can't create second account (or if you create they will ban you again).