It's best to report bugs either via the bug icon, or creating a thread (or adding to an existing thread) in the bugs forum instead of general. Also realize that the devs read everything, but they don't always have a chance to respond to every thread.
The bug icon is good to use, because if you are in game, it should mark in the logs about when you were having the problem, which would help them track down what might be causing it. The threads are good to use, so others with the same problem can post in a single location about their varying experiences and potential player work arounds until the bug is fixed.
If it is something I was doing, I try to explain what I was doing at the time, and the outcome with the bug. Sometimes, I'll include what I was expecting the outcome to be. Often times, the bugs can be things observed without an action on my part, so in those cases, I just try to describe what I'm seeing, and why I think it might not be right.
Give as much information as you can including your Browser, Flash vers., OS, etc. if you know that. Describe the Bug in detail as well as when and where it occurred. Screen shots could be helpful to.
We capture what browser and Flash version you are using, so you don't really have to dig for that. If you are reporting the bug within the game, please try to make it as soon as you encounter the problem. We also get a screenshot the moment a bug is submitted; if there is visual context in it, it can help; but don't expect the screenshot to convey everything- your words and description are the most important thing. What helps us a lot is if this is something reproducible, and if so, what steps you know will cause something to happen again. Err on the side of telling us too much if you can- some reports will just have 3 or 4 words in it, and the player may think we can figure it out from the screen grab or the code in the client error that gets created with the report- and that is rarely the case.
Also- you may occasionally get an automated error pop up with some code in it. It will ask what you were doing at the time with a submit button. (Those don't automatically generate help cases.) If you get a lot of these errors, please also open a help case separate from the information you submit to those. (If you just get the odd one once in awhile, it's probably something temporary.)