Help with Flowers on cake

HI Everyone,
I am complitely new to this area of baking, So I need tips for making flowers from fondant / Gumpaste.
I have made beautiful flowers with fondant but in few hours this flowers didnt hold, I also let them set for few hours. I have made fondant with ( Sugar, CMC, Glucose syrup, Glycerin, Coconuts fat ).
Do i have to add some additive for modelling fondant ?

Thanks and looking forward to know more.

Regards,

Renu