Being a professional rigger for 35 years, I will say right here and now there is only one proper way to lift a spar. A sling and downline. the sling for the hook and the downline being a long bowline over the sling leading down to deck level and clove hitched under the goose neck or similar fitting. Yes you have to go up the rig to set it up, and front side or back side doesn't matter. Real riggers go up and remove wind indicators just to avoid accidently buying one because a large puff caused the rig to spin. although that can be prevented by attaching control lines to the spreader tips while aloft rigging the sling. But if there you are short handed, removing the vane is the best plan. You want the rig to be butt heavy so you can control it. then it's up to the crane operator to know how to properly lay the rig down. Set the butt on a piece of wood and keep the lift cable vertical at all times while the mast is being laid down. This will keep the butt from sliding. on larger rigs a butt bar should be employed to attach the cap and intermediate shrouds to so they can be tensioned and controlled.

I've seen rigs lifted in any number of ways, most work, but are scary, some don't and end up with an epic failure. I've pulled hundreds of rigs using this method with a minimum of crew, and never had an accident.