I always weigh first thing in the morning before I eat and drink and always naked.
I am always 2lb heavier at bed time.
Every Sunday in the morning time all natural!! Lol. Sometimes I feel my clothes will add a pound, so i need nothing on to do it. Also my mom pointed out to me, that I should keep my scale in the same spot when I weigh myself so I will get the right number.
Exactly what THEY said. What you are going for is consistency. Weigh yourself at the same time, under the same circumstances. You know the old cliche: compare apples to apples. If you "always" weigh right before your shower, with just your birthday suit on, right after you've gone to the bathroom, etc., then do that all the time. Because, like Starry said, as the day goes on, you pick up water-weight and you are carrying undigested food.
If you weigh yourself at the end of the day, your weight will probably be 3-5 lbs more than you actually weigh because by that point you will be full of undigested food and fluids. The best time of day to weigh yourself for the most accurate reading is in the morning, before you eat or drink ANYTHING and after you use the bathroom. And I agree with beautifullychaotic, the less clothing on, the better :-)
Oooh first thing in the morning! make sure you weigh your self with the same clothes on too. I always weigh myself with just my bra and undies on. That way if you have jeans and a tshirt on it will say at least an ounce more or so.