I have been doing something that is supposed to be forbidden when dieting - weighing myself everyday (sometimes twice!).
I know that weight can fluctuate in very irregular ways but I always keep this in mind when I step on there. At night, my weight is consistently 4-5 lbs heavier than it is in the AM.
I find it motivating, regardless of what the scale says and it helps to keep me on track all week. If it fluctuates up, I work harder (add a walk or cut down any extra snacking), if it is down, I am motivated to work harder to see it go down more by weigh in day.
What I would like to do is get some digital scales. I find it quite difficult to get a steady reading on this old fashioned kind - it seems to hover back and forth of the mark. Are digitals better for that?