There are many opportunities around you everyday, but many of us are so focused on our art projects and our tendencies to be a bit introverted that we let those opportunities slip away. Share your art as often as possible. Pull out your sketch book at a coffee shop or book store. You're basically telling the world that you create art.Writers interested in arts tend to ask lots of questions about your work habits and fees so be prepared. Decide on your service...penciler, inker, colorist, etc. Know your turn around time: the time it takes you to complete a comic page. Have a page rate in mind: how much you charge per page of art work. Its ok to be negotiable with your fee but have a ball park figure to start off with. Most clients will find this convenient and will feel a bit more confident hiring you.
Feel free to explore ideas with writers. Many of them have ideas brewing or work with other artists in the past and might be ready for a new project. Use their past projects as a stepping stone and recreate their characters or settings in your art style. People appreciate the enthusiasm and seeing their ideas come life. But be warned, DO NOT USE THIS TACTIC IF THE WRITER IS ALREADY WORKING WITH ANOTHER ARTIST ON THE SAME PROJECT THAT YOUR PITCHING FOR. This will create a rift and in some cases result in legal issues depending on the contract in place between that writer and artist.
Fill your sketch book with other characters and places than the usual Marvel or DC. Make your own. This shows potential clients that you are creative and able to conceptualize ideas outside the usual mainstream.