One of the hardest parts of being creative is actually getting started on a project. A lot of people who consider themselves to be creative have a lot of ideas floating around in their heads, but they find it hard to actually get going and put it down on paper. I have had this problem for most of my life, but recently I've thought about the projects I've done in the past that made me feel the most creative and tried to put together some of the things they've had in common, both things that I've done and things that have been forced on me.
Envision the Project
The second step in every project, after the general idea, is how you are going to communicate that idea. Will it be a novel, a comic book, a video game, a poem? If it's going to be a comic book, for instance, how long do you want it to be? How big do you want it to be? Color or black and white? On paper or online? Self-published or published by someone else? Try to picture what the finished project will look like in your hands. Think about the size of the pages that you've decided on; how much art fits on those pages? Think about the number of pages that you've decided on; how much story fits in that number of pages? Think about the incidental things-- the front cover, the inside front cover, the back cover, the inside back cover. Are you going to make it a wraparound cover? Are you going to put a list of the characters on the inside front cover? Are you going to put in sketches on some extra pages?
Obviously, not every one of these questions needs to be answered or nothing would ever get done, but it's good (and rare, in my experience) to have a sense for what the project is going to be like, at the very least.
Sometimes these are set for you by your choice of medium, but oftentimes, when working on your own projects, there is a sense of infinite possibilities for any work. While that has its upside, it can be crippling when it comes down to the nuts and bolts of getting things actually done. In this day and age, with computer colors, print on demand, online publishing, non-standard formats, and the convergence of media, the idea of formatting to the requirements a certain medium seems awfully quaint. But you know what? You have to commit sometime, so let's hear it, champ. You may decide you're going to do a ten-page story. You may decide you're going to do a 24-hour Comic. You may decide you're only going to use a certain kind of pen. You may swear up and down that you're going to do one comic strip a day for a year.
Whatever it is, it's your track now, and for all the times that it will feel constricting, there will be just as many times when you are so glad that you have a clear path to funnel your energy, be it high or low, into.
The genesis of the 144-hour Graphic Novel Project was built around wanting to create a graphic novel in a year and fit it into the schedule of someone who works full-time. Therefore, a number of tight parameters had to be set. We chose to emulate the 24-hour comics' page-an-hour pace, which demanded such things as simple tools, a very very loose story outline, working at published size, and for me, relatively unvaried page layouts. These rules, rather than limiting the creativity of the project, shape it, and make it into what it is.
Set Aside a Time
Along the lines of setting parameters, it's important to set aside a failsafe, foolproof time that you will always be able to work on the project with no interruptions. This is important. This deserves a time in your day. If it's every day before you go to work, or every day when you come home before you eat dinner, or an hour before bed, or during lunch. If you set it up, let people know what you're doing, and follow it, then you end up getting the work done. If you choose poorly (e.g. at a time when you have other things going on) or fail to make it a priority (do everything else that comes up instead of work on your project), you will not. Obviously, things come up, but it's important to think about that as a reason to carve out extra time here and there to finish that month's work so you can go into the next chapter with your head held high.
Do NOT fall into the trap of "just working on it when I have the time". That makes it your last priority. Unless you have absolutely nothing going on in your life, I'm sorry to say it will not work.
Don't Do a Bad Job
This may seem obvious, but it's a very fine point. A lot of times when you have an idea in your head for some project you want to do, you expand it in your head until it is so great and wonderful that nothing you could do (at least the first time around) could ever match it. This keeps you from doing it because you love imagining it in perfect form so much. This is Brain Crack.
Now, that's not to say that you should just throw every undigested idea you ever have out there for the world to see, but what I find to be useful is this simple guideline: Don't Do A Bad Job. Decide what you are going to do, set your parameters, put aside some time, and then try your very best not to suck. If that's what you're focusing on, you'll be remembering to develop your characters, have your dialogue sound good, choose your panel design carefully, and draw your characters consistently and well. Worried that the work might just be okay, and not pure genius like you hoped? I wouldn't. Just like running at an even pace throughout the race puts you in position to sprint and win at the end, taking care of the basic, average stuff puts you in the position to have moments of genius come through when they will be most appreciated.
Come on. I know you've got it in you.