Why doe smy BC have crease marks after I apply it to the cake? It doesnt happen all the time..but recently it has started to happen a lot more.
I am using a sturdy cake base underneath. And I use Crisco based BC.
Any suggestion on getting rid of those ugly crease marks!

I don't use Crisco anymore I don't like how the frosting turns out. Do you use milk instead of water? If using Crisco you need to use whole milk to add back some of the fat the Crisco took away. You might also want to add a little extra liquid sounds like your frosting is a little on the dry or stiff side.

I use butter to add some fat to crisco and it works great for me, I use sugarshacks recipe except I use 1 cup of butter to the rest shortening

This has happened to me if I work the icing too long...if it starts to crust and then you go over it with your knife, you'll get a crease. Using a recipe like Sugarshack's will give you a few more minutes to smooth the icing.