I consider myself both creative and analytical. I try to give each unique piece of me the correct amount of attention, but projects do not always allow that luxury. Sometimes a deadline means powering through the creative process. This leaves me with the "I can do better" feeling. In the past, the feeling has been so strong that I end up doing extra, un-billed work. I've hated myself through every step of that self-butt-kicking process.
Mike Speegal gave a great talk at this year's TriConf entitled "Write something, you lazy bastard" (the talk did not get recorded, but I assure you it was at least 2.75 times as awesome as it sounds). The title of the talk very accurately describes the tone my inner voice takes during these stuck moments. The main point was that we need to stop making excuses and put pen to paper, fingertips to keys, medium to canvas; to write crap if it's all we have, but at least write something. Establish a pattern for writing, or in the broader scope of things, a pattern for creativity.
When I sit for seemingly endless hours, staring listlessly into the balmy glow of my monitor, I must remind myself to design something, put shapes to Photoshop canvas, CSS code to the browser, and establish a habit of not being a lazy bastard.
This kind of forced creativity is only forced until it becomes a habit. Forcing is bad. Habit is good. Jamming the creative "on" button over and over is a great way to get burned out.
Looking back into the wake of your creative diarrhea can leave a person with a plethora of negative emotion. Imagine your inner voice echoing the words "I suck" as you realize that pressing-on produced unimpressive products. "It's a pile of crap" you hear the voice say over and over. You begin to wonder if Jeff Goldbloom was right. You start to believe the lie you're telling yourself.
Don't.
Don't believe that voice in your head. Instead, visualize your inner self punching that smug, judge-y, parakeet bastard right in his inner voice mouth. Light his negativity-filled jerk-ass on fire. Stop putting yourself down.
You don't suck. You only think you suck because your work has improved and you're looking backwards. You're learning from your mistakes, and this is good. You're keen enough to recognize your past crap, and you now hold yourself to a higher standard. Standards are great, but don't think for a moment that your new, higher standard should be applied to your past work. That work got you where you are now.
I won't be the guy who pretends to know how to get over a creative block or how to best avoid burnout, but know this: self-loathing is the opposite of helpful. Feed that tortured artist's-soul of yours a dose of self-love for once. Get off your butt and create crap—lots of crap. Build a creative crap palace, and polish it until it shines. Be proud of your crap because you made it from nothing. You, my friend, are a creator of things, king of crap mountain, and worth at least 2.75 times more than the sum of your past creative works.