your weight can fluctuate by quite a few lbs during the day depending on what youve eaten and drank, and in the morning after giving your body a chance to digest and eliminate, you will be at your lightest
weight, which i find to motivate me wayyy more! as for the kind of
scale, ive found even the cheapest scales are fairly accurate. my scale only cost me $30 and only varies by like a tenth of a pound from the scale at the doctors!