Here is the second handout Bob Wiskera distributes at the Weekend Workshops he leads.  This provides advice for troubleshooting after learning the Easy Freestyledrills.
 
What comes next? Some thoughts on Post-Workshop Practice.
Now that you’ve been exposed to how it feels to swim freestyle with more ease and efficiency, you may experience the "it doesn’t feel like it did during the Workshop" syndrome. If that occurs, here’s a short troubleshooting list:

1. If you feel more drag and/or less flow through the water.
Check Balance. Common errors that lead to "uphill" swimming include:
a) Head position: Make sure your head feels completely weightless. Review Superman Glide and make sure your head is hanging between your shoulders. Transition from SG to "Skating" then 3 to 4 strokes while maintaining that feeling.
b) Arm position: If your fingers point up, your hand/arm will "scoop" upwards, taking your head and chest up too . . . and . . . down go your legs. Also remember that overreaching and pressing down an extended arm causes an ‘opposite and equal’ lifting of the head and chest.
c) Core engagement and wider arm tracks maintain lateral stability.

2. Lack of power–little momentum generated as you spear forward.
a) This is often caused by pushing your arm forward from the shoulder. Instead start a "chain reaction" from the back forward: Drive down opposite foot, which helps drive down the "high" hip (weight shift) which drives your shoulder forward . . . spearing your fingertips 1 inch farther.

If you’re balanced and streamlined, with your arm extended along a wide track at target depth, you’ll surge forward with each weight shift. This gives you time to enjoy some glide and set up for the next stroke. Strive to cross the pool in a leisurely stroke or two less.

What happens between strokes is just as critical as how you stroke! That’s why we focused so much on body position and active streamlining. Travel far while holding a clean, tight line. Hang your head and hand as you do.

3. Can’t breathe; disconnecting from the surface (and air)– two common ways.
a) Driving your spearing arm too steeply down will cause you to dive away from the surface and precious air. And spearing uphill hurts balance forcing you to use the extending arm as a "brace."
b) Breathing late–not following the shoulder with the chin–allows the weight of the recovering arm to sink you.

Relaxing the side of my head into the water as my chin follows the shoulder back has helped me keep the laser beam forward when breathing.