aenhancers

Ok, this may be too basic to post, but I find I use it almost every day.
If you hate precomposing layers with rotation on them just so you can place a dropshadow on the layer without the shadow rotating, this one expression placed on the dropshadow 'direction' parameter will help:

-rotation + 135;

I use 135 because that is the default drop down/right.

If you are flopping an object during your animation, you might want to expand the expression with a condition to catch a negative scale X, which messes up the dropshadows direction. Like this:

if (scale[0] > 0) {
-rotation +135;
} else {
rotation + 135;
}

Simple, but useful.
Anyways, just thought I would share it.

-Ryan