The sky is the limit when it comes to character creation, but here are some unique aspects of this chosen profession you can consider.
What do you do when you're not decking?
There's a looooot of fun stuff you can do as a decker. But must people do unplug from time to time and have other professions/hobbies/activities. Basically stuff you like to do,
or do to keep nuyen coming in when you're between jobs.
Some examples of classic Decker work:
Creating fake SIN's (ID's), data steals, money laundering, simsense chip creation, graphic-visual design, BTL creation, forging cred sticks (money), communication encryption, communication decryptions, data cracking, destroying official records, disabling security systems, creating Matrix programs and IC for yourself or others, skillsofts, creating bot programs for the Matrix/drones/machinery or other projects.....
Bootlegging music/movies/libraries and other digital copyrighted data. In a world where knowledge is power, and Corps have extra-territoriality + military to back it up, burning
illegal copies of some copyrighted do-dad and distributing it is big business.
Hermatic Mages in particular rely on copyrighted formulas and library collections (usually stored on datasofts in this day and age) for their magic. Street mages can rarely afford buying a legit copy – so the black market is huge.
Note for Mages: For the very reason of the black market, often the very best spells created are hidden by good old secrecy. The mage or the Corp that owns the mage doesn't sell the good stuff, but will make the spell available to all other mages in the Corps employ via a corporate network somewhere.