Mark Anderson wrote:

I'm a little confused about when it is appropriate to cut flowers.

Someone here recently advised me about a plant that does better with
uncut flowers, but I can't remember what it is.

Reasons to cut flowers/remove blooms: tidyness -- spent flowers aren't
usually attractive; cut-and-come-again -- encouraging (some) plants to
produce new blooms; to bring indoors and enjoy in arrangements; to
prevent plants putting energy into seed production instead of new
flowers or nourishing (to the plant) foliage growth.

Reasons not to cut flowers: promoting seed growth for collection; in
the case of some plants, the seed-head stage is attractive and
interesting; if you want to make rose-hip jam, don't dead-head roses.

Should I wait for the flower to wilt or
should I catch the flower in full bloom and cut it?

Since you're presumably growing it for its colorful appearance in
landsacape, there's not much point in cutting/trimming until the
flowers begin to fade. Although, of course, if you wanted to bring it
in (I have no idea of its suitability as a 'cutting flower'), you'd
cut in the 'just opening' stage.

I'm
getting tired of learning through mistakes.

Get used to it. It'll keep happening. :-)