what is the best way to paint pla
Hmmm, I am not sure there is a “best” way
“With Style.”
I would either 1) try automotive primer followed by a good spray or 2) Ive heard good things about but have not tried Krylon spray paint designed for plastics (Fusion?).
I would use acrylic based paint and an airbrush.
I made this thing. For painting parts
Black or white gesso work as a brush on primer.
http://www.thingiverse.com/thing:81412 for a painted example using gesso as a primer and then painting with acrylic paints.