Titles sell. Get into the habit of writing down any titles which occur to you. You can also write down good titles of published books and articles. Analyse why the title of the published work is a good one.
Not only does becoming aware of titles make it easier to create titles for your own work, but it will inspire ideas for your writing as well. In my own work, I find that the title often comes to me first --- it's a gift from my subconscious.