Has anyone made their own silicone moulds to make flower centers and if so how?

I haven't made flower centers but I have made my own molds. You can purchase a product from Michael's called Amazing Mold Putty. You need to work fast as you only have a few minutes to complete your mold. Molds are ready in twenty minutes. I have made broaches, tree bark etc. If you are making a large mold apply a thin layer to the item you are molding followed by a top coat. I found when I do this I get much more detail of the item I am molding. Go online and search for printable Michal's coupons and you can save 40%.

Thanks for the information sweettreats!