Purchase blender pens from the arts and crafts store. The felt tips of blender pens come in a wide variety of shapes and sizes. Choose ones that best suit your project.
Choose a permanent ink so that your markers will not easily buff out. Permanent ink lasts longer and has more vibrant colors.
Place the tip of the nib into your permanent ink bottle. Turn the bottle over so the ink begins to be absorbed by the felt nib. You can gently squeeze to expedite the process, but squeezing hard will result in ink spills.
Turn the ink upright when a small bead forms at the base of the nib. Wait for the bead to be absorbed before continuing. Squeeze ink into the nib until it will no longer absorb any.