Your modeling paste/gumpaste should be smooth, supple and have some elasticity and stretch. You should be able to pull your gumpaste and it stretches a bit before it breaks. If it doesn’t, you should knead in a bit of shortening/trex. And a little bit of glycerin too, if you have it.
Creativity is God's gift to us. Using our creativity is our gift back to God. Clarky's Cakes 😎