I have attached a picture of my daughter's Team Swim Suit.  I want to make sugar cookies but am not sure what is the best way to mirror the effect (see picture)....one base coat of royal icing and stripes OR rolled marbled fondant with some gel paint? Thank you for your help !

I can think of three ways maybe. Try them and see if you like one.

1. Cover the cookie with light blue/aqua. Then put dark blue over it. Comb through with a frosting comb.

2. Use the "icing plug" method: put light blue icing  plug in clear plastic wrap with one end very loosly twisted; do the same with the dark blue icing. Put Both in a piping bag and pipe them both out at once.

3. Make alternate stripes of light blue and dark blue (maybe stripes of different widths) and drag a toothpick through in one direction, then the other.

https://www.google.com/search?q=two+frosting+colors+combed&client=firefox-a&hs=EPX&rls=org.mozilla:en-US:official&source=lnms&tbm=isch&sa=X&ei=UG5cUs7xOeOgjAKpqoCwCQ&ved=0CAkQ_AUoAQ&biw=1369&bih=756#q=icing+comb&rls=org.mozilla:en-US%3Aofficial&tbm=isch

https://www.google.com/search?q=two+frosting+colors+combed&client=firefox-a&hs=EPX&rls=org.mozilla:en-US:official&source=lnms&tbm=isch&sa=X&ei=UG5cUs7xOeOgjAKpqoCwCQ&ved=0CAkQ_AUoAQ&biw=1369&bih=756#q=marbled+icing&rls=org.mozilla:en-US%3Aofficial&tbm=isch

Shanter- Thank you very much for your prompt reply ! i really appreciate it and for providing the links.  I think I will try #2 and #3.  Maybe a base coat of light blue and sort of "squirt" on the other colors and maybe see how they lay.  I like the toothpick idea too ! I will let you know how they turn out.

Shanter- What do you think of this technique? Except maybe instead of dragging the toothpicks I can be more random?

http://sweetandsaucy.wordpress.com/2009/11/05/tie-dye-cookies/

Whatever you like best. You're the cookie artist.