Usually I have been using cool shaped cake pans or jello molds.

I've made concrete bowls using plastic bowls that DH cut in half and then taped together..those are actually reusable. Pretty much everything I've gotten to use is reusable.

don't leave out the leaves....
actually, today I was thinking about making a 'drape' mold.
taking a pot or bowl and with the cement/tufa, to lather the cement all over it and when it's just at a good set up time..to take leaves and cover the cement. as it cures, the imprints would be on the outside of the container, rather than just the inside of a cast leaf..
I was driving, while thinking about it..lol
that's when a lot of ideas happen.

it was more fun than thinking of where I was headed..
to pay the power bill lol

those silicone baking pans make great molds and they are reusable. ive used mine 4 or 5 times already

Guess i'm not all that creative...i've never made a mold...get some moldy bread once in a while tho....wish they made 1/2 loaves .LOL

I have been slowly making rocks to go around my flower beds. On the Accoutrements or Hypertufa forum (I check them all regularly so I can't remember which one.)someone suggested using plastic bags from the grocery store to create the rock form. Just put your mixture in it, twist up and ta-da. I used them and WOW! It really worked. Thank you Wendy2shoes!

My camera is charging just now. If I can think of it later, I'll post a pic.

I just bought one of those silicone molds you bake in, it's a rose shape, bought it at a thrift store, and the first thing Klinger and I thought when we saw it, was, concrete rose!!! Well maybe I'll make my choc zucc cake first!lol!