How do I avoid ending up with that overly surprised look from a blepharoplasty? How can I be assured that I won't look like one of those stretched, permanently surprised looking people after my blepharoplasty? .

Blepharoplasty. your eyelids should look natural after blepharoplasty. Have your eyes evaluated by a board certified surgeon with expertise in eyelid surgery.
Be Careful. Choose your plastic surgeon carefully. Ask to see lots of examples of his/her work and speak to patients who he/she has helped in the past. Generally, the “surprised look” results from overly aggressive fore head lifting, not blepharoplasty surgery. Best wishes.
Unlikely. It is unlikely that you would get the surprised look from a blepharoplasty alone. You are probably thinking about an overly elevated brow lift.
To . To ensure that you don't get an unnatural surprised look pick a surgeon who can show you before and after results that you like.
The . The most important thing you can do to get a natural result and avoid the surprised look is choose an experienced surgeon. Pick a surgeon that has shown you results in patients similar to you.