I contacted the company about an unopened package of clear StarDust pens that when opened, did not write from the get go. It seems they were missing the silcone balls in the ends of the caps and they dried out. I never even knew that those silicone balls belonged there!
Here is a condensed version of what they said were tips for these pens:
The Gelly Roll pens will write an average of 800 meters. When we fill them we remove all the air bubbles and this is why they don't look full to the end.
It is very important to keep the cap on the pen between uses as gel inks cannot be exposed to air. This dries out the tip/ball chamber. Store pens horizontally.
If you need to revive a pen, scribble in circles for a few tries. There is no guarantee that once it stops it will start again. Heating or shaking will NOT correct these pens.
They not only replaced the pens but sent me 5 extras in new colors!! Good customer service!