I'm sure there has been a post on the subject of ruffly or should I say ragged roses but I can't seem to find the thread. I want to know how to prevent the ragged edges that my buttercream roses tend to get. I've tried thinning the icing but then the roses flatten out or topple over. I've also tried adding piping gel. Just can't seem to get a smooth edge. Thanks for any help.

When it's too stiff or dry, add shortening to make it more creamy. Adding liquid or piping gel will make it too soupy.

There are several reasons that happens. I personally LIKE roses w/ragged edges as long as it's not excessive.

You icing is too stiff
Instead of adding more liquid, add Karo syrup or piping gel and then just a bit.
The tip is closed a bit too much
Take a knife and slip it into the opening and rock it back and forth to widen the opening a bit.
You are new, don't squeeze the bag hard enough &/or don't turn the nail fast enough OR too fast.....whew

Try one of those and see if it help.