Cinematic-style picture looks have been popular for the last several years; for example bleach bypass became popular after Saving Private Ryan. Both Red Giant Magic Bullet Looks (released in 2007) and Tiffen Dfx Digital Filter Suite have a powerful and pleasant interface designed to develop and control looks, but there are additional resources available to After Effects users still without access.
Color Finesse, which ships with After Effects, has both bleach bypass and cross-process presets (and many others) in the Gallery pane of the full interface. For resources on CF, see White balance + more with Color Finesse. For a filmic contrast "look" check out ft-Filmic Contrast and ft-Technicolor, both by Francois Tarlier, which mimic 2-strip and 3-strip technicolor processes seen in The Aviator (explanations).
You can can usually easily recreate Photoshop effects in AE, so check out Creating a Faux Lomo/Plastic Camera Effect with Photoshop Elements by David Asch and HDR Toning Black and White Images by Richard Harrington, How To Give Your Photos a Dark Processed Lomo Effect from Spoon Graphics, and the soft dreamy Orton effect created by photographer Michael Orton. Plus, there are several tutorials for After Effects for making old film looks.
Note: you can also leverage looks in later versions of After Effects with the Apply Color LUT effect or with RG LUT Buddy. There are several ways to generate or apply looks in Premiere CC, including the Lumetri effect and presets (interchange presets with Adobe Speedgrade), Magic Bullet Looks, and other ways listed in Premiere Pro News Notes #05 (Color Edition). Here's Josh Weiss on Lumetri Looks:
Here's some do-it-yourself (mostly video) approaches for making bleach bypass and cross-processed looks:
1) Bleach Bypass: How to do it in your application text by Stephen Schleicher
2) Using Curves to Simulate Bleach ByPass text by Filip Vandueren
3) Simple Bleach Bypass by Andrew Kramer
4) Bleach Bypass Effect by Grant Swanson
5) Creating a Bleach Bypass Effect by Nick at ProJuice. Embedded below, the video shows one way for AE or Final Cut Pro using two layers, or another from Creative Cow for AE.
1) Curvy Cross Processing in Photoshop CS3 at Layers magazine.
2) Cross processing in After Effects by Giovanni Antico (in Italian; Google Chrome translates text reliably)
3) AE Help has a formula for a cross-process look in Camera RAW; something similar is on AdobeTV.
4) Some AE presets are available from Murat Erozturk. and from Pixel Art, which also posted Lomo Effect After Effects Tutorial.
5) In an After Effects tutorial embedded below, Andy Dykstra of GhostRender shows you how to create a cross-process look with some basic Curves.
More generally, there are a ton film looks plug-ins, templates, tutorials, and presets, and though they're too numerous to mention, here are a few.
For more on color, see TaoOfColorGrading.com, especially the free weekly e-mail newsletter ‘The Tao Colorist’.
Ben Brownlee from Curious Turtle has one series on how to add contrast, color, lens effects, grain, and grime to create a film look in After Effects. He covers the basics nicely in-depth, but saves the deepest aspects to demo his "Film Wash" presets. Here's a sample:
Brent Pierce of Cineblur has a set of free Instagram "filters" for After Effects that use Red Giant’s free LUT Buddy app for integration into AE, Premiere, and Final Cut. There's video explanation too.
Magic Bullet Quick Looks Free provides a sampling of looks from the powerful Magic Bullet Quick Looks plug-in. You get a library of 20 presets inspired by feature films like The Matrix, Saving Private Ryan, and Traffic to use in AE and other apps.
Awhile back, Magic Bullet creator Stu Maschwitz posted Creating a Summer Blockbuster Film Look, which shows you how to get the "Summer blockbuster look" of flesh tones and complementary blue-teals. For an antidote to that infectious look, see Teal and Orange - Hollywood, Please Stop the Madness by Todd Miro on his blog Into the Abyss. Note also the free plug-in Magic Bullet Colorista Free, which has functionality still not found in AE or Premiere 3-way color correctors (see the PrepShootPost primer).