I agree on getting the entire backside waxed and all in between including several inches along the legs - I ask my waxers to remove every hair under my boxer shorts so this gets it all. Note that waxing styles, methods, and waxes vary considerably. I like the variety and so I keep going to more than one spa… but if you don’t like one experience, keep on looking.
Some folks ask for help on spreading the cheeks, or helping keep ones parts pulled aside or taught as needed. Still others, handle it just fine on their own. Seems that no-one requires the doggy-style butt-in-the air anymore, so I either lay on my stomach or my side with knees pulled up towards my gut… I must admit that the hard wax is a bit nicer (it is used on pubes, crack and underarms when used), but hot wax is fine as well.
The key is experience on doing it right, safely, and easy - speed is good for both client and provider. And, of course, comfort in working around my nether regions is really important - I have worked with trainees and their reluctance to get in there and work confidently make the experience a bit more painful…