Can't really give you nice tips with text, but if you have Skype, I can share my screen to you and show ya' some tricks. xD I have like 5+ years experience with flash (but I always do suck with cartoons, lol), I'm great with animation and graphics, that I can; and that exactly I'd love to help you with. I feel you're really nice person, so, I'll let you use me as you wish! Haha! xD Later. ;D
~ Art
Kuoke
I'm going to say that you really don't have to detail your backgrounds, simply because if you can compose your scenes well enough, you should be diverting all the attention of the viewer to what you want them to look at. If you're focusing on the backgrounds, at that instance, it should be detailed, but if you put excessive detail into the background of a scene where it either last 2 seconds, that's just extra graphical pressure and kilobytes.
Also, if you study depth of field, try to observe the fact that things begin to lose detail as they reach further into the horizon, thus, if you were to detail your backgrounds again, excessively, they'll appear as if they were in the foreground (as opposed to being in the background, as they should be).
And that's enough about backgrounds. I'll leave with the note that what the audience sees is 90% their personal perception of what they conceive the coloured shapes and figures to be - not what you try to convince them the objects to be.
Syringes
Thanks! That helps a lot and I completely agree and understand, I am glad you pointed that out to me ^^
I like to focus on the event rather than scenery so I think I kind of got it so far : D