Five years ago as an undergraduate I found this compact messenger bag at Fossil.
It cost approximately $130 at the outlet.
In the last five years I’ve used the bag consistently as a graduate student, a student teacher, teacher, and freelancer.
The color itself has been extremely versatile in dark brown. The messenger bag’s best quality is its strap — I bike with it strapped to my chest and and carry it to meetings, freelance work, and other odd jobs. It blends well at a modern day office.
A strap immensely helps since I prefer hands-free bags and easily forget belongings.
Fossil’s pebbly grain leather is definitely inferior to what you see with bespoke or high-end MTO materials; but it has admirably warded scuffs and damage from downpour.
If you want to scale up in formality, you’re looking at leather portfolios followed by briefcases or attaches.
This isn’t a proper bag for suits because of its casual materials; but a structured messenger bag in all leather may work.
This bag pretty much fits the bill: convenient, durable, and subtle.
Fossil’s interior pocket design is convenient, but not perfect; it’s a nice surprise since most brands get pockets wrong.
In time I’d consider designing a different bag with the same versatility as this one (though probably not in grain leather) with improved quality. The hardest part will be selecting a maker.