Practice and more practice, then when you think you got it
More practice !!
No, that's the way to get to Carnegie Hall: "Practice, Practice, Practice!"
Seriously, often one needs to just practice the 10 pin during practice sessions. Take your first 2 FULL games and do nothing but throw at the 10 pin, Then 2-4 games of normal strike practice, then finish off with at least 2 more FULL games - 20 balls of doing nothing but 10 pins.
But you've got to throw your 10 pin ball the same way every time, using the same starting position and the same target and keep your eyes on your target until the ball rolls over it.
If you practice this type of regimen for a few weeks, if your 10 pin percentage doesn't improve, you may need to take up knitting or crochet.