While understanding GD&T is very important, so are the basics of drafting, from view projection to dimension placement. Too many engineers consider themselves to be good drafters because they made good grades in a CAD class or three. There is much more to drafting than being able to use a CAD program. While it isn't as popular a method as it used to be I find the best way to learn is to suffer repeated corrections from an experienced checker. An engineer may be able to get all of the pertinent info down in a drawing but miss the objective of making the info clear, concise, and capable of only one interpretation.
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV