Hmm...
1. Your hand should be (in my opinion - ignore me if you completely disagree) palm up when you hold the treat.
http://www.youtube.com/watch?v=RnPVBe9X_ew <<<---- My amateur attempts!
This way you can teach the hand signal at the same time.
2. Higher value treats!! Something slimy and smelly usually does it. I used cut up chicken or turkey hotdogs, string cheese (beware of the gaseous effects later), tuna chunks, all kinds of things. You want your pup to be intent on you.
3. Watch Me should be getting harder and harder. If Duncan isn't focusing at agility, I'll take out a treat and hold it to the side. When he ignores it and stares at me, he gets it.
4. Clicking happens the exact moment the action is correct. When her behind sets down on the ground, click and then treat.
5. You are saying Sit too soon. I wouldn't attach Sit with the activity until she is doing it quickly and consistently with the hand signal.
You are doing so much correctly, though! And Fluffy is sooo pretty. Beautiful tri!