To make a rose—
Well, there are actually several ways. The easiest way is to take some other flower and simply push it into the shape you want. In which case, ink and a bit of determination are that’s required. (Florists tend to do use this around Valentine’s day.) However, since the spell wears off after a few days, this really only works on cut flowers that are going to be thrown out anyway.
Or you can take paper, cut it up and glue it into the proper shape, and write the spell on it in the right kind of ink. Do it properly, and the rose will stay a rose, although it will go brittle as it ages. This is often used in high school magic classes as an example of an organic-to-organic switch.
The hardest way is to take a chunk of granite, etch the spell’s lines onto the surface, and then bleed on it. The blood makes it easier to shove the stone into the form of something else, something ephemeral, although the task’s still difficult enough. But if you manage it, you’ll have a rose that won’t fade or fall to pieces, that can’t be crushed. And it will keep like that for as long as your will was strong at the instant of transformation.