so, when i started knitting i did lots and lots of things wrong, because well, no one told me not to. so, here's a couple of tips i've learned. post a comment if you've got some you've learned that i haven't listed.
always slip stitches purl-wise unless told otherwise.
except in ssk, for which you slip knitwise.
always slip the first stitch in every row unless told otherwise.
if you want to untwist a stitch that is laying on your needles wrong (unless you knit combination) knit/purl in the back loop. it'll automatically untwist it.
so... what's you fave tip?