folding and unfolding template free to use.
Require After Effects CS6

iPad like animation transitions for layers or comps. It's included in-out transitions.

Plain and simple, Film Flash is an automated, dynamic preset for After Effects that bumps up the exposure of the footage to create a cool transition effects between two video clips.

SplatterType is a preset that will allow you to create amazing ink and paint splatter animations with just a few clicks. Based on a special font type.

A very useful expression to automatically fade in and out based on the layers length.

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

Create your own dynamic transition effect in After effects, Simple techniques along with Particular will be explored

Richard Harrington has an article up at ProVideo Coalition for After Effects that allows you to move projects from Final Cut Pro to AE.(from Popcorn Island)

Learn how to create a morphing effect from one graphic element to another using fractal-noise animation. You will learn how to create a map grid with interactive animation. Use brightness animation to control the fractal noise for an organic transition effect.