I always try and do this very thing in my Shattered World campaign. I have distinct 'schools' of magic, co-existent and competitive. So I make sure that I name spells to indicate somewhat of origins. I may also go down the path of reworking a spell somewhat to go with the different approaches taken by different wizards. For example I have magic missile, arcane bolt and levin bolt - all variants of the magic missile spell (for reference, the middle one does d6+1 damage per bolt and requires a ranged touch attack, the last allows a Fort save and does d6+1 damage per bolt). These three spells come from different 'schools', and have been stolen by others over the centuries.
All in all, it adds to the feeling that magic is an ongoing work, rather than just the parroting of the works of the ancients.