I always wash my yardage fabric. Not the charms or Jellies. I like it this way. Saves on the bleeders, scratchy and no good...
Measure twice, cut once.
Buy the best you can afford and depending on usage, go with what works. A dog quilt is fine with lower quality fabric...if you are spending hours on a heirloom, then spend the money for quality fabric.
Change needles often...seriously, is it worth the aggravation of a few pennies.
It's your craft and your signature....how do you want to be perceived?
Do what makes YOU happy!!!! Never settle for less!!!
K