Do you need to create a custom control for your preset? Instead of doing the tedious coding, let the Expression Controls Creator write it for you.

Sliders hooked up to provide easy rotation looping.

The CountdownTimer preset uses expressions to make it easier for you to create countdowns.

A few simple expressions to convert from dB to volume-Percentages, this way sound will respond more like opacity...

With this Preset you can create noise that woud appear on a TV with bad connection, you will find these kind effects for example in Horror Movies like 'SAW', spy movies etc.

This script reads a user specified text file and
creates a text layer for each line of text in 3D space.

A great time-saving preset to "duck"(fade in/out) a music layer based on a voice over.
"Ducking - Audio Terms Explained - Process of automatic compression, eg when the announcer's voice signal causes the level of music to be attenuated."(from lp2cd.com)

Another cool use of the "linear" Function

Film Burn is an Animation Preset that automatically creates the overexposed "roll-out" effect, where the tail (and the head if you want) of a clip flickers into overexposure. By Stu Maschwitz

In this episode of Red Giant TV, Aharon Rabinowitz gives you some cool tips for working with numeric text, for things like video game scores and other digital readouts.