I have just come through one of the most serious cases of creative block in my illustration career. The really stressful part of it was that I kept saying yes to jobs (because I needed them) but was really short on creative inspiration. Fortunately, I was able to push through, but there were some moments when I felt like I was going to have to surrender to failure.
There are many reasons for creative block, but I think it comes down to two root causes: lack of confidence and distractedness. In the case of the former, it is not that I am less creative, but I am more doubtful of my ideas. Because of this, I am less motivated to push my ideas past the notional stage: they don't get a chance to prove my doubts wrong. In the case of the latter, I am simply not in the right environment for creative sparks to really ignite.
I think that distractedness is actually very broad and includes many possible factors, including environmental, circumstantial, and psychological. Having the right environment is really important. Personally, I need large chunks of time where I am free to sink into a creative flow and the confidence that I will be able to stay there until I'm done. It's hard to sink into this when I know it will be broken at any moment by a knock on the door, a hovering creative director, or in my recent case, a crying toddler. In this case, a change of location, whether temporary or permanent, usually helps. Sometimes just switching it up and setting up camp in a cafe for a day is enough to get focused. Most recently, I had to move my studio from my home/bedroom (where all the commotion of domestic life were streamed live all day), to a separate studio away. This almost single-handedly cleared up my creative congestion.
Circumstantial distraction can arise with any life event such as illness, moving, stress, etc. For some kinds of creative tasks, these can often spur great creativity. But in many cases, they debilitate and cause us to switch our focus from abstract, creative thinking to attending to our wounds and putting out fires, so to speak. In such cases, it is usually necessary to give time and space for these events, knowing that they will subside soon enough.
Psychological distraction, actually quite related to a lack of confidence, is attitude based. It simply refuses to produce anything and provides all manner of excuses why it shouldn't. What is so tricky about this kind of distraction is that there's nothing outside yourself you can change to make it go away. You can't find a new studio space or wait to get better — you must face some inner demon, push past it, and this takes the most strength. And in this case, the only thing to do is to do something — sometimes anything at all. When this kind of distraction gets to me, I find the following things help to push me through the blockage. (They are very specific to my illustration process, but hopefully they have their universal equivalents):
Just start sketching ideas, no matter how bad they seem. I often get anxiety at the sketch stage, worrying that I won't come up with ideas that will end up as great illustrations. In such cases, when I am thinking straight, I know that I just need to sketch, sketch and sketch more thumbnails, without critiquing them too much. Then, I leave them sit for a day or whatever time I have available. After this time I come back to them and see them with fresh eyes. Sometimes I see something promising that in the moment seemed doomed. In these cases I am able to refine the ideas and ready them for presentation. In other cases, I am not quite satisfied with anything, so I know I need to keep sketching. At a certain point, when I am repeating myself or when time is almost up, I know I have to stop and work with what I have.
Place the best ideas in a presentation deck, even if they still seem unrefined. Rather than despair, I choose to have faith in my ideas. To make them seem more plausible, I start placing them in my presentation board and proceed to write rationales for them. By doing this I am able to home in on actual concepts and themes, and the writing part does much to clarify my thinking. It is usually at this point when I realize I have something, and I am either ready to send to the client, or I am able to go back to more sketches with confidence, making refinements, and then sending them off.
No matter what, don't despair. Do not be overcome by anxiety. No matter what the cause of creative block, there is always a solution. In a very recent illustration commission, I could not for the life of me come up with ideas. Instead of freaking out, I articulated, first to myself, and then to my client, what I was having the most trouble with. By so doing, I was able to secure a bit more time for the project, and I didn't feel alone in my struggle. The client agreed it was a difficult piece and offered to bring the writer of the article into the brainstorming process. This proved to be just the thing to help set me on the right track. I was blocking because I felt I didn't understand the article or how the client wanted me to approach it. But including them in the brainstorm, I was able to glean important insights about their visions for article and art direction, and knowing these insights gave me confidence to present some sketches. And for the record, I aced this project — the client was delighted in the end. The bottom line is that creative block is ultimately an inner struggle that has less to do with talent or creative strength. If you can push past your doubts, push past your excuses, and work, work, work, you will overcome.