I have tried a few times to add a fondant balloon on a wire to a cake and have failed to get it to work. It either falls over or the wire is too heavy (I'm guessing) because it leans and makes a mess of the cake or the fondant figure I tried to have hold the balloon. What is the secret?

Try using coffee stirers , insert the wires into the stirers you will need to cut the stirers the height of the cake, then insert the wires into that push them down into the cake even with the top, i did a BDay cake for saturday and used them they held the #16 straight and then i had stars coming out of the cake at angles worked great, Hope this helps also it makes the wires food safe,

So simple, yet so effective. Thanks for the tip. I will try that next time.