I like the idea that fairly often a formerly-human dragon's first shift into full sized true dragon form is way, way slower and more ponderous than it will be once they master their shapeshifting nature. Like it takes hours or even a few days and then they're stuck in their big and inconvenient but oh so Right new true form for a while, maybe even weeks or months, until their shapeshifting powers more properly develop....
Bringing takeout to your in-the-process-of-transforming dragon roommate (dragon as of like, a day ago) only to find that over the course of your workday her wings have sprouted and she's frantically trying to clean up all the books she knocked off the shelves in the process but is having trouble picking them up without ripping them up with her half-formed but very sharp claws.
She's all apologetic and embarassed about it but you tell her it's gonna be okay and she'll get used to it all soon enough~