A while ago, Stamped developer Andrew Bonventre did an ObjectiveSee interview. My favorite tidbit:

Create a key-binding for the “Simulate Memory Warning” menu action in the simulator, then simply hold down the key combination so that it’s continuously firing while you click around your app.

I found it non-obvious how to do this since the /Developer directory has moved into the Xcode bundle. So here is how, for future reference:

1. Open the directory containing the iOS Simulator app in Finder, e.g.:
   • $ open /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/Applications
   • System menu → Recent Items¹ → Move focus to iOS Simulator with arrow keys, then type ⌘ ↩.
2. Go to the Keyboard Shortcuts panel:
   1. Open Keyboard settings.
   2. Switch to Keyboard Shortcuts tab, select Application Shortcuts.
   3. Tap the small + button.
3. Choose the iOS Simulator as the Application:
   1. Choose “Other…” from the Applications list. A file dialog appears.
   2. From the Finder window we opened in step 1, drag the iOS Simulator into the file dialog’s search box.
      
4. Set Simulate Memory Warning as the Menu Title and assign a shortcut, e.g. ^ ⌘ X (better than M for right-handers, because you will want to keep it firing with your left hand while clicking through the app with your right hand).
   

There you are. Fire away!