to get it really shiny you use clear pipping gel but if just want a nice sheen i use apricot jam diluted in boiling water work really well! just try not to touch it once it is coated in the fondant as the shine will remain slightly sticky and your finger prints will mark on it, but if this does happen just paint a bit more over the spot and it will blend
i saw on the ultimate cake challenge that a contestant/challenger used a small ball of fondant and rubbed that over the fondant you want shiny-i've also seen buddy on cake boss use steam a lot. steam would be faster i think. let us know how it all turns out and good luck!
Another vote for steaming! I've started steaming almost all of my cakes to quickly clean off the stray powdered sugar. Some cakes, like my recent Mickey cake get steamed a little longer to help make the colors pop and shine. The red and black were dull pre-steam - after steaming his ears were really shiny and red looked great.
I've done the shortening method and it looks great but after awhile it dulls quite a bit, not back to what it was before but def not as shiny. The scarecrow in my pics was shortening rubbed and was SUPER shiny but you can see it now.