Mostly animations inside After Effects is created with keyframes. It might seam a convenient way to do it, but it’s much easier to achieve some animations with expressions. They give you bigger control or even allow to achieve things that would be nearly impossible to achieve by manual key-framing.
Dan Ebbert from motionscript.com has put together some useful Expressions. If you watch his examples they might seam a bit childish and not applicable to real situations, but actually they are. Here I took two of them to create this example logo revealer. You might find others useful as well.
Make sure to check other expressions on his Expressions Lab section to learn new skills and find some ready made solution for your projects.
Random Grid Movement
Here is another example that is based on one of his Expressions. This time it’s Random Grid Movement. See the expression and original example here and now watch the video to see how powerfull this expression actually is. If original example didn’t inspired you – this one will for sure.