You want a tip on how to practice doing "show, not tell"? Here's one I've always given:
Go watch a movie. Better yet, pause the DVD at your favorite scene and replay it. Now, start writing the scene: from describing the setting, location, background, etc. to the characters to the dialogue and action.
Do not summarize. Do not "tell" us things like "she's hungry." Do not interpret the scene for us. Focus only on what you can report on: facts, action, things that you can actually observe: "She rummaged through the garbage, then took out a half-eaten apple and chomped on it, then swallowed the core, too." Describe things in terms of the five senses: sight, sound, taste, smell and touch.
Do it in details -- don't skip, take your time -- until you can completely recapture that scene in literary form and the readers can experience the same thing without ever watching that scene themselves.
The next best thing is read some screenplays. Not for prose, but for the way they write scenes after scenes of "show, not tell" and yet still convey the emotions, thoughts, etc. of the character clearly.
The Green Mile is a good one to start, so is The Talented Mr. Ripley. But really, just pick up any award-winning screenplay and study.