Before forever stamps, if the stamp price went up I’d just use 2. It probably cost me 5 bucks over the course of a few years, but I’m young enough that I never sent that many things by mail to begin with.
I did a signature card for my bank approximately 2 weeks after getting married and changing my name. My signature 15 years later didn’t look like my signature back then. My husband’s been signing the same name for much longer and his didn’t change during those 15 years.
Regarding stamps, I bought Christmas ones. Supposed to be church windows. I’m not convinced.