While i wait for my resin to arrive so i can cast this mold for the gems, I decided to tackle the horns.  I have seen horns done using expanding foam as a base, horns that were sculpted and cast using medium such as silicon, foam latex, and resin.  Even some made out of fiber cast, I wanted to take a different route that was not as messy or time consuming.  I decided to go the route of using badding foam, i went with the semi stiff variety, the type that could bend and be used in shipping or to stuff cushions or be used as barrier for water pipes that sweat.
The other reason i chose to make it out of this material Is that it will be very light, and when i add the wonderflex to it, it will retain a great amount of that lightness yet be resilient. 

Here are some pics on that progress:

I took the  foam and basically rolled up into 3 sections of different widths then duct taped each section separate.

 Then i cut 45 degree angles on the ends and joined each section one at a time and taped the joined parts together.

I also added a bit more foam here and there to get it to look like this:

Nice and lightweight, they are ready for the wonderflex  and fossshape treatmeant!

Oh a side note about using this kind of foam, I found it is generally better to purchase it online then at your local store since it seems to absorb the smells from all around it.  It can get a be stinky, lol so if you guy straight from an online distributor you will be mostly stink free.

If you are pressed for time, and cannot wait for it to be shipped to you, then just spray it with ya fave cologne or perfume and after a day the smell will barely be noticable.