See, I try to memorize how things look every day as I go to school, home and uh... well, that's pretty much it
So! I've been thinking and came to quite an interesting conclusion, methinks. Imagine you're in a bus. What do you see? Seats, windows and poles, right? Those are probably the first things you'll imagine when thinking of a bus. Now, however obvious it seems, say to yourself "why are those things here"? The answers are simple - for people to have places to sit, to see where they are and to be able to hang on to something. That was easy, right?
Now, focus on the details. When I imagine a background, an environment, the details are always blurry because I just don't know what belongs there, even if I've seen it a billion times before. When I was on the bus today, I saw lines under the "STOP" light (no idea why that's there, either, eheh). And it kinda sucks to remember things as "random lines". So, I examined the thing a little more, and saw that it's a door and a lock, sort of like a little built-in box. I have no idea why it was there for, but I assume some emergency supplies could be stored in the box. Or I saw nails on the floor - to hold the seats in place.
See where I'm going with this? I think it would be much easier to remember something when you know not just that it's (usually) there, but because it's there for a reason.
Of course, you can't do this with everything and not always completely accurately (we all know humans have feet and joints and whatevs, but still, it takes looots of practice to draw them right) but I reckon keeping this in mind could provide you with some basic guidelines, whaddya think? ^^