Becoming an expert at camouflage takes time.
This is true even if you were born with a knack for it that you inherited from basically every other 3 toed box turtle who has ever lived.
All things considered, some of your disguise ideas will just work out better than others.
So it can be a good idea to try out new disguise ideas before you really need them to gauge whether they are as good as you think they are.
You can identify the really not-good ones by trying them out on your large shell-less assistant, who typically can’t spot you unless you are standing right on top of her feet.
If she sees you easily, you know you don’t want to use that disguise ever again.
