Does anyone know how to make asters out of either buttercream or royal icing?
Regular butter icing would be the way to go for piping. You can colour it, flavour it etc. I use 2oz butter to 4-5oz icing sugar, and put a drop of whatever colour you want into it and mix really really really well - the more you mix it the lighter it is. I bought a packet of Dr. Oeatkar tubes of coloured stuff for writing.
Best of luck with the baking - put up a pic and show us when you've it done.
I just googled 'aster' and found this is another flower that grows/blooms in a zillion different versions
Exactly which version are you wanting? Then I can help you
Post a pic of what you are looking for. Some of what I saw is basically nothing more than a daisy; others are multi layers
of short rounded petals.