the ground has a lower elevation around the
corner and it will cause a 6" gap underneath the fence. It looks weird
if I were to do this and I don't want to have a gap and try to mediate
it with soil, stones etc... Do you guys have any ideas on how to deal
with this. Looking for someone with experience in this.



If you want it even across the top, obviously you'll have to trim along
the base, or vice versa. You'll lose 6" around most of it this way.
One way or another you have a decision to make.

Not a huge problem as long as you have a water level (or an actual
surveyor's level) to lay it out & measure, and then a good saw.

it would be a bigger problem if you needed to trim higher than the lower
horizontal framing member on the fence panels.