Beyond this, consider how these professions might vary depending on who the customers are - nobles, or lower class. Are they good at their job or just scraping by? Do they work with lots of other people or on their own? City or village?
For younger characters:
Apprentice to any of the above
Messenger/runner
Page/squire
Pickpocket
Shop assistant
Student
Looks after younger siblings
(Images all from Wikimedia Commons)
Also consider:
Candlemaker Ferryman Factor (looks after business for an employer in another city) Tiler Cutler Beekeeper Apothecary Interpreter Furrier Moneylender/Banker Winemaker Tinker (small trader who repairs stuff) Nightsoil collector Customs officer
Also a bonus for animal related professions: Fowler (supplies game birds for eating) Warrener (catches rabbits on your land for you to eat) Ostler (looks after your horses) Falconer (looks after your falcons) Cocker (looks after your fighting cocks)