When our exciting graduation takes place, most of us will be faced with the harsh drawback that the probationary privilege levels will rise to their normal levels. So everybody loses privileges! Meh!
Counteract this by voting!
Do this: You know how sometimes from a question, you go back up to the questions link, or maybe back to one of the tags, or to a hot network question? Well, every once in a while, if you read a particularly nice question or answer, click their user page! Give another one a shot. Don't be too fast or mechanical or anything. There are vote-fraud protection scripts in place. Vote the post up or down (or comment) on its own merits.
Do this: Go to your favorite tag, and browse from the oldest page backwards. Some neglected gems back there, friends!
Do this: Get some voting badges. Vox Populi, Electorate. Shiny, shiny!
Do this: Vote on a proposed site name. I know, I know. They've already picked one. But you need the practice!
Do this: Keep your eyes peeled for nascent moderators, gonna be some voting pretty soon!
Do this: Post More ideas below.