Easiest way I distinguish between a half and quarter is that on the quarter two leaves from the wreath line up almost perfectly with the two legs of the R. On the half, those leaves and legs are offset.
I've been very lucky with my detectoring; 3 nice Barber dimes from two separate locations in my town. Note: lack of any gods on the dimes! Cold, hard cash....
Third star from the top on right side - on the half, it is perfectly 'square' & the left star tip aligns with the front (tip) of the nose - on the quarter, that star is slightly rotated to the left and its left tip aligns below the tip of the nose