recently hooked up with civvie that had those little barbells that pierce the nipple.  wasn't sure how to handle as I did not want to be overly aggressive and cause any pain.  I love a lot of  tit play especially nipple sucking/fondling.  what do you fellows do?  how about clit studs ???

..Some like it gentle, and others rough.

The problem for some fellows here is that they are here due to a difficulty in communicating effectively when it comes to sex and intimate relationships -- so in theory the voice exists but in practice it needs lots of practice before it's really a voice. Maybe these are the first steps in exercising that voice

I like them, and like to flick my tongue against them, both the labial and nipple ones.

That's all well and good, but that voice needs to be directed to the appropriate parties, not here.

little steps  Think of it as practicing in front of the mirror.

...the women I spend quality time with are usually intrigued and want to play with it. Every once in a while, I have to ask her to go slow & easy until we get a bit more ramped up -- not too much pulling right away, watch the biting, etc.

I am shocked...shocked I tell you, that there is a disconnect between the sexes.  

Mine are pierced...personally I like light gentle kisses
You can always ask what she likes and go slow, adjusting technique based on her reaction.