Google Autocomplete – go to google.com, start typing a phrase and look at the dropdown autocomplete results. You can use the underscore character “_” to have Google fill-in-the-blank. Just make sure the last character you type is an underscore. Try using plurals and change the word ordering to see different results. This is how I find 90% of my keywords.
Cafe Press: This website allows you to create digital designs that can then be sold on the platform. You'll earn a commission for everything that sells and you'll never have to deal with logistics like printing, warehousing and customer service. If you have some graphic design skills, then this is a great potential source for your web-based income.