Prep your nails by covering them in a base coat. Allow the base coat to dry thoroughly.
Open all six bottles of nail polish. Place them in a row where you can reach all of them easily. Put them in rainbow order: red, orange, yellow, green, blue then purple.
Paint a thin red stripe from the bed to the tip of your thumb. Make the stripe at the extreme left edge of the nail. Use a thick coat of polish.
Paint an orange stripe right next to the red one, from the nail bed to the tip. Add stripes in the rest of the colors until you have covered your nail completely. Don't worry if the stripes are not exactly even. With tie dye, the look should be individualized and not perfect.
Place the point of a straight pin in the center of the red stripe. Drag the pin across your nail from that point to the top of the purple stripe. Place the pin back at the beginning point in the middle of the red stripe, and drag it toward the purple stripe, but aim for a spot lower on the stripe.
Make four or five more drag marks on your nail from the red stripe to the purple one. Each time you drag the pin from one side of the nail to the other, you will create more of the tie dyed effect on your nail.
Do the other nine nails in a similar manner. Allow all the nails to dry completely.
Paint on a top coat to protect the polish. Allow the top coat to dry completely.
Experiment with different combinations of colors and different placement of the stripes, such as running them horizontally or in curves, just like you would experiment with tie-dyed clothing.
Use a very thin brush instead of a straight pin for a slightly different effect.