using small guage is great for learning hand patterns and knot control…seeing how the twisted will look later on and roterope dexterity…all natural fibers for body touch and sytnhemp, amsteel or tech12 for haul lines…

http://www.versales.com/ns/theatrical/rope.html
https://www.ropeinc.com/stage-sampson-am-steel-blue…
http://www.samsonrope.com/Pages/TechnicalAspectsRig…
http://www.onrope1.com/level1-course.htm

if rope fails around her body, the effect on her will be a bit our of being ropestoned until you rectify with another hank of rope…
but any thing else makes lack of knowledge incredibly dangerous…
take all the classes offered by your local BDSM, watch rope-topia, etc

my first rope on a girl was in 1958, a piece of well worn sisal that was in a garden…