Oh yeah, I can relate! And please don't interpret my reply as a self-proclamation that I'm "there", because I'm still very much a beginner. But like everyone else has said, it does seem to get better!
The first time I used my 400D, I was so excited because when I viewed them on the camera, they looked great. You can imagine my dismay when we got home from vacation and discovered at least 2/3 of them were totally useless - blurry, too dark, blown out, etc. etc. I was in manual the whole time.
I've since learned, if shooting something that's a "take it now or it's gone forever" type of picture, get out of manual! Use an auto mode best suited for that situation. I recently tried to catch shots of birds hopping around the yard and quickly discovered that sports mode suited it best - not only did the camera adjust the shutter and aperature, but also the ISO and focus lock. All I had to worry about was trying to control my camera shake! Sports mode shoots at higher shutter speeds so shake is greatly reduced.
Having said all that, I honestly think I've learned more by spending the last two months in mostly manual mode. At first, it feels like nothing is sinking in, then slowly you'll notice you're starting to piece things together. I'm still not even close to consistantly decent shots, but when I do get one good one in manual, boy, there's no feeling like it! Remember - you'll learn far more by the mistakes you make!
And I don't know why, but I was holding off using a tripod for the longest time. My brain kept saying something stupid like "...real photographers don't need tripods". D-uh! The difference is incredible - if what you're shooting allows you to use a tripod, do it. Obviously there are instances where it won't be possible, so in those situations, take several shots. I read one tip that suggests using continuous shooting because if you take 5 or 6 at rapid speed, chances are one of them will be nicely in focus
Take a few shots and check the histogram. Even though I was following the exposure meter in the view finder, I've discovered (at least with the kit lens) that it consistently under-exposes. I've learned that in some situations, I need to ignore what the camera tells me to do, and instead compensate the exposure a little over what it recommends, and the results have been better. I can't repeat this enough because this is where I've learned the most - check the histogram!!!
Jane