Engine lift crane, Yard crane, block & tackle over first floor verandah, 14" truck ramps ( must be flat topped ), axle stands under the caster mounts lifting the mower with piano straps and even 1/2 way up the trailer ramp.
Have used them all at one time or another.
Ramps can get in the way of the blade nuts so axle stands are my prefferred on site method.
Slip a strap over my shoulder and hook it to the caster wheels, shorten the straps to give a good lift with my knees and kick in the axle stands.
ZTR's are very light on the front end.
If I have brought them I reverse the rear wheels onto the ramps first .
Now lifting the back, that is totally different.