Uphill opening gate
Sometimes you need to place a gate on sloping ground - say at the end of a driveway. This can cause a problem when the gate needs to swing against the hill, since you may not be able to fully open it without it hitting the ground.
There is however a simple trick that can solve this problem, just by adding an offset to one of the hinges.
Modify the bottom hinge
You can modify the bottom hinge to introduce an offset to the side of the gate that needs to open against the rise. For a small rise this might just need a normal hinge offset toward the side of the post, and the side of the gate. For a more dramatic rise you will need a dogleg in the hinge to move the pivot point further away from the gate:
Now when the gate is closed, the matching offsets in the two parts of the hinge keep the gate in line with the post, and it all hangs nice and straight:
However when you open the gate: