Here's my setup-a lot of it is personalised of course, but I think some things would come in handy for everyone:
From anywhere I can triple tap home for a flashlight. I chose this because it's hard to do by accident, but still very easy to use without having to unlock etc.
I often remove all background apps, so I find a shortcut for this very handy-flip mute switch twice.
I have spycam too, quicker to take a picture, however I think the app could be improved. I hold the power button whilst in lock screen.
The following 3 come in handy for me a lot as I often listen to music without the headset: holding up skips a track, holding down is previous track, and short hold on the home button is play/pause. I use these most days, I love the fact that now I don't have to go into the lock screen first to skip a track or play a song. These buttons can be used from anywhere too, which is handy when in app etc.
When I am on the springboard I figured the home button was useless-if I want to search I will scroll my screen to the right! So I reassigned that to take me straight to the iPod. As a result, home screen now switches me between iPod and springboard-which is great!
Finally I have used up then down to launch FB. I use this the least, but still handy when I feel lazy!
Let me know what you think of this setup, or of you have any other ideas