Over the past few months, I have taken up an apprenticeship in Berkeley (And will begin another in June). My duties, so far, consist of archiving work done at the shop, along with designing and printing my wedding suite, which we call "practice."
A few things I have learned:
Don't print too quickly, take time to look at every print.
A little bleed is ok, as long as it isn't text!
Let your tools dictate the design.
Begin with what you have, build your design from there.
When setting type, set your longest line first. (This often changes once I start.)
Everyone I have met in this printing community are very kind and generous.