Drawing tattoos is fun but when you get stuck for design ideas it's not so fun as you could get frustrated by having to think about drawing what you love to do, the process of coming up with quality tattoo concept ideas can flow quite easily if you take the following into consideration.
Draw on interests - Your main area of interest you could specialize in and create art based on what you find easy to draw, for example you may like fantasy art, so you can draw many things in this area, like dragons, warriors, dwarves or anything, so long as it gets you thinking about your drawings with solid ideas.
Creative atmosphere - Often in a creative environment when you work with others or you have art on your wall and you are relaxed you can come up with more ideas than you can handle and this is good and can make the difference for your many ideas to flourish, watching a movie while you sketch is one of my favourite ways to be creatively inspired, especially if it's an action packed special effects bonanza that appeals to that part of the brain that subconsciously takes snap shots of all those wonderful images.
Free Drawing - When starting to draw freely without concentrating too much, you don't exactly know what you are going to draw but it's a very useful exercise to try and some of the ideas that you generate can inspire you further if not now, then another day, so keep all of your drawings and concepts in a safe place for viewing when you get stuck for new design material.
Source : http://ezinearticles.com/?Drawing-Tattoos---Tattoo-Ideas&id=3300021