Personally I use both lips and tongue, one at a time, i.e top lip on the clit first and then the tongue and then to bottom lip so
its not just the tongue wagging back and forth on the clit......... Most times the reaction is "Where the hell did you learn to do
that?" i.e girls enjoy it immensely! a couple of gentle bites with the lips or even teeth (if you do it gently enough) and interspersed
with tongue as deep into the vagina as possible, usually keeps my girl right in the zone........