Make sure your firesteel is very close (touching probably) your tinder bundle. Then I think it is easier to hold the striker stationary and firmly against the steel, then pull the firesteel back against it. That makes aiming the sparks at your tinder much easier. The blade from an old hacksw makes a great striker. Lots of sparks, but it really eats up your firesteel quickly. Not a problem in a true survival situation unless you plan to need your firesteel for a very extended length of time. Take a small chunk of hacksaw blade. Use the non-toothed side for "normal" things, but use the toothed side for true emergencies where you really need to get that fire going pronto for survival.

Also, when firesteels are new there is a coating on them. You have to wear off that coating before you get down to the meat of the firesteel where the big sparks develope.