Clamps placed in as many places as you can think to place them. Maybe see how many you can get onto each part. Maybe add some weights to these if the pain is not intense enough for her. Clover clamps are best for this - the more you pull them the more they bite.

Chemical methods - deep heat or toothpaste (toothpaste is less intense than deep heat) on the nipples and clit, fresh cut ginger root in the arse (do some research on figging). The pain starts small but builds over time and gets worse when you add water. Though some people find it less intense than others (depends on your skin sensitivity).

A combination of hot wax and ice can be exquisite. Ice can be very painful after a long exposure to it then you add the hot wax to push it to the other extreme.