weighing in objectively
Whether weighing in daily or weekly, it's important that we look at the number with some objectivity and not beat ourselves up over inevitable fluctuations.
Overnight weight gain or loss is usually from increased carb and/or sodium intake, both of which retain water within your body.
Obectively, if your scale reads 1.5 pounds more than it did yesterday, it's not likely that 1) you took in 5,250 extra calories, or that 2) your body turned them into fat overnight.
When I weigh every day, I take the week's worth of numbers and average them. Then I look at the trend (on average) from week to week. That seems to help me. It might help you, too.