The pick point for the mast is at the center of balance which will vary for each mast depending on whether it is a single spreader or multi-spreader, keel or deck stepped, and what other stuff is attached to the mast (radar, winches, speakers, etc.). Generally, the pick point for a simple single spreader deck stepped mast is just below the spreader and a few feet above the lower spreader for a keel stepped double spreader rig.
@Allan12210 photos show the pick point and shows a line from the pick point down to the base of the mast. The mast is lifted from the base the loop around the mast helps to keep the mast from going horizontal too quickly.
Once the mast is clear of the deck, the crane operator should begin to lower the mast while the mast butt is walked forward. The mast will pivot around the line looped around the mast with the weight being transferred from the line at the base of the mast to the loop. If the crane operator gets the pick point correct the mast will hang horizontally without any assistance. More often than not the mast will be a little butt heavy which is more desirable than top heavy.
Our mast is unstepped every fall, been doing that for 42 years and helping with dozens of other boats.