Tips I can vouch for:

• Staci Perry (VeryPink.com) has a great video showing how to alternating skeins when using hand-dyed yarn.  She demos both flat and in the round.  Almost every time I need to learn a new technique or need a refresher, I check Staci’s YouTube channel first.
• What to do with that last fiddly stitch when binding off.  acengineeredknits
• Judi’s Magic Cast on video – thanks to Cat Bordhi
• Lisa Stockebrand’s Knitting backwards video.  It shows how to do it without twisting your stitches.  I searched all over the place for this because most videos demo a technique where you end up with twisted stitches.
• My go-to sock heel – the Fish Lips Kiss heel by Sox Therapist.  Worth much more than the $1 you’ll pay.  PattyJoy has a new heel coming out soon and I can’t wait to try it out.

I haven’t tried these but want to share them anyhow:

• Tightening a baggy neckline: http://www.yarnharlot.ca/blog/archives/2008/02/24/hooking_because_i_have_to.html
• More complicated knitting backwards demo which has multiple stitch types: http://youtu.be/Or0xftjwxYk