What I've found that works in my Clark is to have the foot end just a little bit higher than the head end. Now to do that I can either tie the tree straps on one side higher or I can adjust the whoopies so the hammock is off center with the foot end closer to the tree or if the ground is on a slope, the foot end is tied to the higher tree. I've found that with the foot end only a little bit higher, that it seems to feel flat when I'm inside the hammock. If I've not got it right, I can tell it after a few minutes of laying in the hammock.
Something to try... after you set up your hammock, lay in it a while. Do a bit of tossing and turning to simulate if you had slept over night in it. Then try getting back up. When you swing your feet out, are they over your shoes?? Or are the shoes shifted to one side? If they are not under you, then you've slid down inside the hammock. That will show you which end of your hammock you've gotten to high.
When I've set up my hammock just right (with the foot end just a little bit higher), when I get up the next morning, my feet are pretty much right over my shoes.