I share your inability to slice consistently. The only way I have
managed to improve is through repetition. The same way I learned to
juggle (lots of failures). If you keep slicing eventually you will
get better. If a slice it too hideous to use, save it for bread
crumbs. Make lots of bread and you will have lots of chances to practice.
I make smaller denser loaves and have some better results. Even if
your slices aren't as pretty as the store loaves, they will be
healthier and tastier.
Take care,
JD
Tumwater WA