I have to weigh every day.
I am a major procrastinator in every aspect of my life and it's too easy for me to fool myself into thinking if I slack off on something now I have time to make it up later.
So when I used to go to Weight Watchers some years ago, it was very hard not to overeat after my meeting because I had a WHOLE WEEK until I was going to be weighed again in which to make up for overeating that one day. Weighing every day prevents me from playing that game.
Weighing every day lets me see, claim, and celebrate the fluctuations downward as well as the fluctuations upward.
I keep track of my "current low" even though on any particular day my weight might be a pound or two up from that current low. And it's very helpful to me to see all the fluctuations, start to learn my body's patterns.