There. I said it. Inconsistent shadows make me twitch.
So what, you might ask, are inconsistent shadows? Look at your desk (or whatever is sitting around you). Look at the objects on your desk. They all have shadows, and for the most part, the shadows are all on the same sides of each object, based on the light source in your room (the window to your left, or the lamp to your right). And while there are some factors at play (the light from your monitor might cast a different shadow than your window which is your main light source), for the most part, all of the shadows are going in the same direction.
If you were or are a paper scrapbooker, the same would be true for your layouts. If you have a big window to your left, then all of the objects on your page will have shadows on the right sides. The shadows might vary in depth and softness, but they would all be on the right.
The same should be true of your digital layouts! Everyone has their own preference for the direction of their imaginary light source. Personally, I love to have my imaginary light source come from the bottom left of my layouts. For whatever reason, I love the look those shadows have. And for that reason, pretty much all of my pre-shadowed elements have their shadows on the top right (the opposite side of my bottom-left imaginary light source. Have I lost you yet?).
You, however, might prefer a top left imaginary light source. So as you are setting up your layout and choosing your bits and pieces, you should constantly be thinking about which direction your imaginary light source is pointing! If you have a button that has a bright glare near the top left, then you know that designer used a top-left light source. If you don’t want to use a top-left light source on your layout, then you need to ROTATE THE BUTTON until the glare is in the correct spot for your imaginary light source.
I’m not gonna lie – there have been times that I have changed the shadow direction for an ENTIRE LAYOUT based on one element. If I am using an element that has text on it but that also has an obvious imaginary light source, then I will change all of my other shadows to match the shadow of that element.
I know, I know – sounds like way too much work. But trust me … it is SO WORTH IT! Once you have mastered this, you will be amazed at how much more realistic your layouts appear to be!