I quite liked the idea of component based magic from sorcery is a sword without a hilt. Here is a 5e version specifically built as a self-taught wizard type. This only works if you use slot based encumbrance – which I do. Rise Up Comus is worth a read and I don’t do it justice here – somewhat on purpose as I want traffic/purchases to go to the authors website where you can get much more flavourful component explanations and magical disaster.
Encumbrance. Instead of tracking the weight of something you track encumbrance in slots. You can carry a number of items equal to your STR with no issues. These slots represent your backpack/storage items on stowed or on hand. Carrying over this amount means you are encumbered and all ability checks (and related skill and combat checks) have Disadvantage – your movement is reduced by 5′ for every slot of encumbrance over your STR. For more generic items like treasure (or other edge cases) 400 gp or 5 small items is equivalent to 1 slot.
The School of Natural Magic
The School of Natural Magic is made up of self-taught wizards. Loved or reviled by the locals they tend to either take up residence in a town or become itinerant and sell their magic abilities to the masses. Called hedge wizards or witch, members of this school are the common mans wizard. This is a wizard archetype.
Beginning when you select this school at 2nd level, you can only cast spells that have a material component, but do not require a spell book. You know all the spells for particular level but can only carry the components for spells you can cast. Each component counts as a slot per spell level of encumbrance. However, because you are not formerly taught spells can get out of control when you cast them. You roll a d20 every time you cast a spell, on a natural 1 you suffer an arcane mishap. Roll on the wild magic table for the effects.
Starting at 6th level, you may select an archetype ability from another school of magic that is 6th level or lower.
Improved Component Magic
Beginning at 10th level, prepared spells take up half the number of slots to a minimum of 1 encumbrance slot.
Starting at 14th level, you may select an archetype ability from another school of magic that is 14th level or lower.