Whenever I get new pens, or paints or papers, I have to try them out as soon as possible. I was at Ikea recently and they had the holiday merchandise on sale. To my surprise, their were some sets of metallic and colored gel pens. They didn't have a manufacturer's name printed on them so I have no idea where they came from. They weren't a very fine tip - I would guess they would be similar to a number 5 pen.
In the tile above I tried out a set of gold and silver metallic pens. The gold pen didn't show up well on the black paper, so I went over it with the silver, which obviously does show up well. If you look in the smaller orb, you can see some spidery lines where I tried the gold pen.
These are very simple strings - two circles - but they gave me a quick way to get going with my pens. This string also made it simpler in that it limited the number of tangles.