Aww
Threads die after a while; once they go past the max page, it 404s, so if you don't see a thread, start a new one (after lurking for a while.)
Also, if you want cute things with a male, go to /cm/, if you want a thread with a female who is cute, then here's the place for you: /c/, but if you want cute animals or whatever that's anime, try to start a thread on /a/ about cute things

There's no search, so by browsing through the 10 pages. older threads are automatically deleted, so it's often case a specific thread doesn't exist.

There's an addon for Firefox that adds some useful functionality for 4chan pages. http://www.4chan.org/tools/
For example, it adds an arrow button, by pressing it moves you to next thread, it also switches pages when used on last thread of a page.

use of the phrase "noko" in the email field will take you back to the thread you posted in last.

once there, or if you see a thread you like, click the 4 leaf clove symbol next to OP's name to save it as a favorite, which are usually in the top left corner of the screen.