As an artist,.. I like to do the shaving myslef.
If my cliant shaves the spot and accidently nic’s him/herself then there will be a small scab there. We can not tattoo on scabs,..and we cant just pick them off and tattoo it.
IMHO leave it to the artist to do all of this.

My mentor had me place a ball point pen in the place of a tube and grip.
I would run the machine and do line art.
worked great for me.

P.S. There is no such thing as a “Tattoo Gun” It is a Machine.
Gun’s shoot bullets.

Lighter tones of color will not show on you for very long.
You always have to remember that your natural skin tones will over power the pigment.