I will soon be attempting to dive into the world of RKT and I was wondering if there are any paticular 'tools' or around the house type objects that you guys may use to help with the shaping and molding process. I'd like to make a princess castle cake and I was thinking of making the turrets out of RKT - but I'm not sure how to get a consistent cylindrical shape. I'm curious as to what items some of you may use or could recommend. Thank you kindly.

cram it down some PVC pipe?

That's cute that you use those popcorn eating guys when you're so patiently waiting. I may have to borrow that idea since I never got a response to a question I asked several hours ago btw, I just now noticed your post.

I have never tried to make a perfect cylindar shape, but I can give you some other tips for molding that work well.

Run your cereal through a food processor just a bit or put them in a baggie and use a rolling pin to make the cereal finer. This helps get a stronger bond when you mix with the marshmallows and a less bumpy surface. Use less or no butter in your RKT recipe. That will make it more firm and it will dry harder and more durable. After shaping, cover with candy melts (a couple layers until it's nice and smooth). Candy melts also help with the durablility.

I guess if I was going to try for the cylindar shape, I'd just roll it like I would a rope of fondant while it's still warm. Still thinking about it. If I come up with something else, I'll let you know. Hope that helps a little anyway.

I don't have any tips about RKTs but I can't stop laughing at those popcorn-eating smileys, lol. So cute.

I don't have any tips about RKTs but I can't stop laughing at those popcorn-eating smileys, lol. So cute.

If you look in my photos, you will find Oscar the Grouch. His head is rkt. I shaped it like a football shape (softened a bit) and while the rkt's were cooling, I did some molding. I kept going back to the piece as it cooled to keep shaping. (I shaped for eye sockets)
The 'Bumble' also has rkt in his head. I forced the rkt into a bowl. (the top of the head) again, I kept checking every few minutes and pressed and shapped as the cooled (only for about the first 30 minutes, I'd just keep checking)
As I melt the marshmallows in the microwave, I throw in a block of white molding chocolate. (about two ounces) then I just mix it all together.

I hope this helps. It's really not a rocket science, you just gotta jump in and have fun!
Good Luck!
*I recently pm'd someone about turrets and rkt. She said that she opted to not use the rkt but just used fondant with tylose, shaped around a tube (like paper towel tube) and let try.
Hope this helps!

Another idea for turrets is fondant or gumpaste covered ice cream cones, they're the perfect shape for the top of turrets.