Panel lines?

I've searched the forum but can't find anything (weekend alchohol perhaps?). I would like to do panel lines but am not sure how. I don't want to experiment and ruin some good paint jobs.

I have painted them before but not anymore, just buy these http://www.scaleracecars.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=S&Product_Code=srcscriber and you will never think of panel lines again. If you have painted the body allready just put light wash of darker colour of the body (if it is red put a bit of brown or some black in that red), delute it good (5 times thiner one time colour) and let it run down the panel. But I am sure it is in FAQ somewhere. Just type panel lines in search.

Gundam marker pens