I don't ban any spells at all, however I reduce all spell slots across all spell levels by 1, to a minimum of 1, for all regular casters.
This results in a 33% reduction in spell slots total, and is more in line with our 1-2 encounters/day playstyle.
Furthermore, I give these casters an extra option, they can cast a spell even when they have no spell slots left, at a cost of one level of exhaustion each. They're never truly tapped out, in a huge emergency they can make some magic happen.
This only applies to the casters affected by the reduction above, so no half-casters and no warlocks.