ROLLED FONDANT is a good medium for decorating on.There are all sorts of things you can do. To start, cover the cake with Fondant following HOW TO COVER A CAKE WITH ROLLED FONDANT.   

Impressions: It is important that you apply impressions right after rolling the Fondant while it's still soft and pliable, otherwise you won't get a good impression. HOW TO. There are now stencils that can be used not only for stenciling on a cake, but also for embossing. You simply roll out your Fondant to the thickness that you want, place the stencils over it, and with a light pressure, pass your rolling pin over the stencil. You can keep the design as is, or go one more step and lightly dust the raised impressions with powdered food coloring. Do this before lifting off the stencil. 

Another way is to press a woven doily into it. When removed, it leaves a beautiful impression. Lightly dust the top of the fondant with powdered sugar or cornstarch. This will keep the doily from sticking. Place your doily (both cloth and/or plastic work) item on the fondant and GENTLY press the pattern into your fondant or roll over it with a rolling pin. Remove the doily and brush the additional powdered sugar form the top of the cake with a pastry brush. 

Pale luminescence: when Fondant has dried, you can "paint it" with an artist's brush dipped in edible gold petal dust.

Coloring Fondant: Often when you cover a cake with white Fondant, it too, must be very white, unless you are covering it entirely with icing. If not, the color of the cake and its thin layer of buttercream or glaze may show through. You can tint it! It can be colored in a wide variety of hues.

Tint Use paste food colors to dye the Fondant! Liquid food colors will make it too wet and water down the icing and will not give the same intensity. Also, water-based food coloring will melt the sugar-based Fondant and the color will come off with every brush stroke!

The one exception to this rule is when using an airbrush food colors with an airbrush, they are water based. With the airbrush, you're not brushing and the spray is so light, it won't melt the fondant.

To add color: Add a little bit of color to the Fondant at the end of a toothpick dipped in the paste color. Knead, knead and knead in the color before deciding to add more. To add more, use a fresh toothpick every time you dip it into the color. Make a little more Fondant that you'll need because it's nearly impossible to match the color again once if you run out!

Shape colored Fondant into disk and wrap in plastic and place in an airtight container if not in use to keep soft; Fondant will dry out. Note that colors will darken slightly overnight and will fade if Fondant sits on a "dummy cake" in the light for any amount of time.

"Paint" on Color: Once you apply Fondant, you can "paint" it with food color in specific areas.

You want to use a dry, powdered food color, not paste or gel. Moisten the color with lemon extract grain alcohol, such as gin or vodka, instead of water. Alcohol doesn't melt the icing because it evaporates quickly, leaving the color on the Fondant. I prefer to use pure lemon extract, readily available in the grocery store and it contains more alcohol than than gin or vodka (87 percent), so it evaporates more quickly. Make a mixture of the powdered food color and the lemon extract so it resembles milk. If it streaks, it's too liquidy, so add more powdered food color; if it's too thick, add more lemon extract. Test with a small piece of rolled fondant to get the proper "paint" consistency before applying to an entire cake.

To do, mix 1/2 cup royal icing with glycerin until it is the consistency of cream. (1/2 cup of royal will cover a large cake). Deep colors work really well. The addition of glycerin will make the "color paint" workable for a longer time. Glycerin is a good choice for a large cake, however water would work for a small cake. The humidity of the workroom will influence the working time. Add color and mix until evenly distributed. Pour a portion of the color into a flat tray or platter. 

Colored "edible" luster powders: For subtle colors you may want to try the powdered dusting colors that Gum paste artists use. They are sold in cake supply shops. They come in tiny containers and remind me of powdered make-up. You apply them with a loose brush or dry sponge and they add a very natural light dusting. A pale wash of color can be painted on the icing (mixed with lemon extract) and allowed to dry, then a fairly dry brush can be dragged across to give a wood grain effect. This is why most artists that make gum paste flowers use them, they will give a beautiful natural look to handmade flowers.

Crimping: While Fondant is still soft, use a pastry crimper to crimp a decorative edge around top of cake. 

Weaving: Small vertical slits can be cut at intervals around the cake with and Exacto or Detecto knife (from art supply stores) so short pieces of ribbon can be inserted. This gives the illusion that a ribbon is woven into it.

"Tying" a  color coordinated ribbon: (gold lame and grosgrain are my favorites) or even a chocolate one around the Fondant covered cake can be done, and is exquisite. To attach a "ribbon", Then, pin one end to the cake. Wrap it around the circumference, overlap the ends and secure with a second pin. Pipe tiny beads of royal icing with a number 1 or 2 decorating tube or with a parchment cone, along both edges of the ribbon all the way around the cake. Remove the pins when dry.

Ruffles: For swags, roll the Fondant as thin as you can -- you can almost see through it. You will need to strengthen it by kneading in some Gum-Tex. It will then hold together and actually firm up good enough to hold the sway. Don't use this mixture to cover the cake though. Make sure you keep the surface under the Fondant dusted with powdered sugar or it will stick when you roll. It cracks if it gets too dried out. (Choco-pan Fondant is moist and easy to work with, so you might try it, instead).