Well... I'm not confident if my English is enough to publish a tut... hmmm... let me try!
Not always we can comply the rule of needle exchange every 8 hours of use... but we can easily notice when the needle is not as sharp. I'll show you how to make your own sharpener at home.
Cut a 7"x5" rectangle in cotton fabric. Sew around the edges, leaving a small opening and forming a little bag. Place inside a piece of steel wool. Close it with little blind stitches. Ta-da! You're ready for sharpening your needles.
All you need is to sew (needle without thread) this sharpener forward and backward, just a few times!
Make a little bag
Sharpening your needle