ahhh, an area I have some experience with... not necessarily good experience but here are a few tips that I have learned about in tank photography. Some or all of these may be obvious to most but it took me countless hours to figure it out. Maybe because I'm a slow learner.
First of all, make sure your glass that you are shooting through is spotless.
Flash reflection - I have found that a 30-45 degree angle(up, down, sideways) to the glass and keeping the camera lens as close as possible reduces this to almost never an issue.
Blur - this is mostly from movement. I have to rest my hand on something or use a tripod to keep from blurring my photos.
Missed/blurred shots from digital cameras - This is where you miss the shot you wanted because there is a delay from the time you push the button to the time the photo snaps. This is how it was explained to me. Almost all digital cameras have a 2 stage button. If you hold the button down half way, the autofocus adjusts constantly while you are holding it at the half down position. While holding it half down, if you press it the rest of the way down, you will get the picture you wanted as it will snap right away. I hope this makes sense... I am obviously not good at explaining it as I have spent hours trying to teach my wife this and she still doesn't get it. One more note, the batteries will run down more quickly if you are using this method as the camera requires more power to constantly refocus so just be aware of that.
