All girls are different. One size doesn't fit all.
Very much so, some will like hard, some will like soft, some will like a lot of tongue, some prefer suction, some like a play around, some straight to the point, some like fingers with it, some not, even a rare few will like teeth, and more options beyond that. If OP wants the WG to enjoy oral then he should just ask them to direct him. Expecting the same technique to work for all is folly.
If he just wants to dine down town, then he should do what he enjoys within what the WG allows.