unsure WHERE to measure?!!

dme1977

when I take my measurements im kinda unsure where EXACTLY is the waistline im supposed to measure ... is it up high right under my ribcage or is it where my hipbone starts (like when you put your hands on your hips) ??? also kinda the same question for the hips do i measure down low on my hips or high like where i put my hands on my hips?? ... and what if i only have a regular measuring tape.... do i use a string or something then measure that???!!!