For really small PE parts like bolt heads, screw heads, I just stick them on the end of an exacto blade till I cyano them onto the model.
You can't see any mark afterword.
For larger parts up to 1/24 scale hoods and down to parking light lenses I use a Vacuum Pen. what's that you ask?
It's a pen shaped hollow tube with a tiny suction cup at one end and a manual or electric(in my case) vacuum pump at the other.
Here's a pic.....
Mine has a finger hole on it that when you put your finger over it the little suction cup will hold the part. When you let go of the finger hole the part is let go. Really slick.
They can be had for as little as $12 for a manual one, to over $200 for a fancy one. I got mine because my girlfriend works in a lab as a chemist, and thought it would be perfect for little parts. She was right!
