Thanks again for the nice comments!
Wow!....tats are great, something i always had problems painting and why i never got around to painting my 150 central american indians.
ps...Does the gangsta dude in the first pic get a chance of damaging himself by spent shell casings smacking him in the face! 
I would't want to paint tattoos on 150 minis! That said, I "cheated" a bit. I drew them with a 0.3mm waterproof black marker before blending them in by using diluted washes.
He's a gangsta! He doesn't care about shell casings smacking him in the face, or incidentally hitting anyone, as long as he can strike a cool gangsta pose.
Hi again, do you mind me asking how you cut the bases, I have recently done some of these using pvc packaging, drew a circle and cut out with scissors the edge I got was pretty sloppy compared to yours.
It's not too bad but yours is much better.
Cheers
I use a circular disk cutter (note the plastic sheet looks white because of the protective layers that need to be peeled off):

You can find many models on eBay if you type "circular disk cutter".
I spent quite a while experimenting with various materials. Anything above 0.5mm becomes difficult to cut cleanly. I settled on clear 0.5mm styrene and glue the minis to the base with superglue. One downside is that this is too thin to pin the miniatures to the base. Initially I was worried about that. However, it is actually not a problem. The bond between resin/plastic and even metal minis to the base is pretty strong. I had one accident and the mini's heels snapped rather than it coming off the base.
And, finally a mini-progress update on the last mini I did yesterday a bit in a hurry. I give you Aisha, Queen Sharifa's tame cheetah. It's from Northstar miniatures. The global proportions aren't too bad but I wasn't happy with the head and paws, and resculpted them.