Many good replies. Level ground is best. The 3 point hitch travels in an arc motion. It is perpendicular to the ground in the middle of it's travel. Using pallets or stacking blocks to use as a "parking stand" is getting the 3pt closer to being perpendicular.
Some smaller implements (sub soiler, boom pole, ect) while reasonably light and easy to man-handle, I have built wooden parking stands while implement was attached to tractor and 3pt in it's center of travel position.
If interested, photos posted here.
Get the most benefit from your quick hitch. Buying new get QH compatible. Here is a photo of an implement whose manufacturer has their act together. Note how it's designed for cat 1 & 2. Also the lift arm spacing can be adjusted. Some "QH compatible" only need minor modification. This TSC...
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