I've never done a dummy cake, so this might seem like a stupid question. Do you coat the dummy with BC before adding the fondant? (The thing is, I've never done a fondant cake either! But this is for a competition, and I figure if I can pull it off, the fondant will work great.)

Just spritz a little water on the dummy and the fondant will stick.

Thank you, leahs! Now I just have to figure out how to make it look like it isn't my first attempt.

I coat my styrofoam dummies with a thin layer of crisco and then lay the fondant.

Thanks sbcakes for your suggestion. I might have to experiment to see which works best for me. It's going to be a small cake, so I should have plenty of time and materials to work with.

GeminiRJ you beat me to the punch I was going to ask the very same question but thanks. I have another one in the same line do you have to cut off the edges of the circle to get the contour shape or can you cover as is. I know the edges on the dummies are a little sharp and I don't want it to tear the fondant. Also since it is only a dummy will the yucky Wilton Fondant be good. Don't want to spend the money on Satin Ice is I dont have too.

I don't soften the edges of my dummies...but others do. I roll my fondant out thick enough where it doesn't tear. I was reading a post that someone else had posted asking the same question, and people were saying to soften them a bit, because that is what it will look like with real cake and your customers won't be expecting those sharp edges. A little bit of water I think should soften those edges.
As for the wilton vs satin ice. I had the same thought too, but after I compared pricing I found that Satin Ice was no more expensive than Wilton...can you believe that? I buy my satin ice from either CKproducts.com or CakeDeco.com and buy it in 20 lbs tubs at a shot.
HTH!

I use a new emery board to file and soften the top edges of my dummies.

I also have never done a dummy cake but am making a cake covered with Buttercream. Can I cover my dummy with royal icing and then ice of it with the buttercream to match the rest of the cakes?

I roll mine thick enough to cover, but one other poster once said she pushes the edges against a hard surface to soften them. I think that was a great idea. Also, yes, Wilton works great for dummies --buy it in Michaels with your 40% off coupon and it is a great savings. I've also used MMF, and Michele Foster's Delicious Fondant on dummies. I just use a little piping gel like glue on the surface and a few places on the sides. Works great and comes off later as well. I just peel off most of what will come off which is quite a bit, and then use warm water to wash off what didn't. That way I can use the dummy more than once.

edited for typo.