All I can think of is to get a pair of pants that fit to you liking to measure by. Either a pair you have or one at the store.
Salena

Something I had to learn...don't keep tapering 'til the very end of the leg. You may have to taper back out where your hem starts or go straight for a couple inches so that you will have enough fabric to "reach around" the leg when you turn the hem up...Otherwise the hem will be puckered.

From the hips, on the outer seam, sew along the seam, and gradually sew inwards, untill the turn of the hem and start stitching outwards towards the original seam. Do the same on the inner seam from the crotch, best to hand tack first and try on, to see if its OK.