I admit that I'm "magnesium challenged"...maybe it's supposed to be easy to use but I don't have much luck with it.  It takes forever to get a decent pile of shavings, then they like to blow away.  And when they do actually light they seem to "flash" burn before I can get anything done with them.  And it's not a cheapo Dones bar, this is a big soft block from Firesteel.com.  I even got a bag of mag turnings from eBay; those suckers need exposure to naked flame.
No, for me it's 1) Tinder Qwik, 2) cotton balls (naked, waxed or PJ'd), 3) fatwood and/or 4) Weber grill lighter cubes.  To light them I've usually got a lighter, a firesteel, a Spark-lite and matches.  What can I say...I'm a pyro!  
 
 BTW, forgot jute cord.  I've had good luck with it, but it does seem to wick up moisture out of the air fairly easily.  If I have jute it's gotta be sealed in something.