After growing up in an area that was filled with red-brick clay if you found a mud spot keep it wet or rinsed off. So far even on the east coast where the mud isn't all that sticky aiming for the center seems to work best. I don't go crazy but keep enough cadence to stay moving if a rock or stick is hiding. The worst thing seems to be edge around it or try to trace the wheel tracks of trucks gone before. The center 'between wheels' hump seems to be in most cases smoother. In my last XC race (Michaux Teaberry) it was many mud bogs, some almost a foot deep. Using that strategy kept the buildups down and ended up almost cleaner at the finish than in the first mile. Of course The worse thing for trail maintenance is to ride trails like that if they are not maintained afterwards, and the worse thing for single track is to skirt around it, making it wider.