How to Get Secret Avatars on TeenNick.com

First off, if you have no clue what a Secret Avatar is - I'll direct you to TeenNick's FAQ.

Now, the easiest way to get Secret Avatars -
Play Rank. A Lot. For a while.
Secret Avatars are found the same way creds are, (through activeness on the site) but they usually require more time to get them. (You'll know you've found one when you see the blue box pop up in the same place creds show up). Sometimes this can depend on how rare the Secret Avis are, occasionally you'll get some of the common ones when you're doing regular stuff on TeenNick.com, but unless you regularly spend a ton of time on the site, you might need to put a little more effort into getting some of the more rare ones. (Playing Rank is the easiest & fastest way to do so) If you can manage to set up a laptop where you're sort of doing homework and clicking on Rank with your toe - that can work. Plus it'll exercise your toe. Switch the rank subjects if you start to get bored. (Note: Secret Avatars aren't found in any particular spot, going to a certain page will not make them show up - going though a lot of pages will.)
Keep the volume turned up to hear the Creds chime. Usually you tend to get a ton of creds when all you want is Secret Avatars. Which can be awesome, though you can always occasionally ignore them if you wanted.
If you do find one and it doesn't show up in your collection right away - don't freak. They can usually take a few minutes or even an hour to show up (especially with re-released older Secret Avis,) but they will show up eventually.
That being said, make sure to regularly check your Secret Avatar collection, sometimes we find them and don't realize it. (You can see your avatar collection by going to your main profile page and clicking "View Secret Avatars" under your full body avatar.)

If you get tired of all the Ranking - take a break and take some quizzes. Some have popped up that give away Secret Avatars like this one about Beyond the Break! (You do have to get all of the answers correct, but you can redo it until you do.)

 Don't forget -  Activeness really just means that you're going through pages on the website, so you can still find Secret Avatars while reading the Message Boards, looking at the @TeenNick blog, playing games, reading articles, checking out peoples' profiles and pretty much anything you'd regularly do.

Here are lists of Secret Avatars as compiled by The-Seth. (Who we still miss.)
Degrassi
South of Nowhere
Instant Star
Beyond the Break
Radio Free Roscoe
Moesha
Girls vs. Boys
Dawson's Creek
Other (Halloween, O'Grady, Daria, Best Friends' Date, Miracles Boys, Whistler)