I used this technique in a recent card and I just wanted to expand on it a bit. Here is the card:
A drop shadow is a visual effect that gives the impression of a shadow
behind an object. Use the Hello die and cut two coordinating cardstocks.
The one which will be a shadow should be a darker colour. Decide which
direction you want the light to be "shining" and attach the shadow by slightly
offsetting it from the "raised" Hello die cut. Make sure it's showing
equally around all letters and attach them together. Don't offset it too much or
it becomes a distraction! Use a colour that will coordinate with some
other element in your creation, but don't use something too wild and
crazy. After all, this is a shadow, something that ties the overall design together and accents the main word, not a feature element!
Thanks for drop shadowing by!