First thing in the morning. Naked. After going to the bathroom but before taking a shower or exercising (I don't want to count sweating as weight loss, and I don't want to weigh wet hair).
I won't weigh after I've had anything to eat or drink. I won't weight later in the day. (Although I sometimes weigh for fun right before going to bed. I lose about 3 pounds while I sleep. The evening weight is never recorded, though.)
in the morning after I go to the bathroom in little or no clothes. This isn't to say that I don't weight myself more than once which I know that I shouldn't but that's the one that I take as the official weight.
I get up, pee, then take off my pj pants and weigh in my t shirt and undies. I exhale while getting on the scale (hey, air weighs something, right!). Sometimes if it seems too high, I will weight again after I have, um, pooped, which is usually later in the morning. Sometimes that makes a difference, sometimes not, but I take the lower number when I do weight pre and post poop!
I do the exact same as you, Rebound, to the letter....I refuse to have on a stitch of clothing. I have weighed myself at night and again the next morning to see the difference. I average about -2lbs overnight.