Every kind of packaging should be from some (very clearly visually distinguishable, e.g. with a mandated specific color) single recyclable/compostable material. No more mixed-material packages of (non-biodegradable) plastic film stuck to cardboard. No more one-off specialty plastics for packaging. No more wrapping sheets of plastic around everything. No more Mylar. No more plastic single-piece candy wrappers. No more loads of plastic tape everywhere. A lot more cardboard / waxed paper food packaging. Etc. And vendors should pay whatever the full lifecycle of their products/packaging costs.
It should be possible for every consumer to easily clean and sort their waste into a relatively small number of bins, or for a recycling sorting center to easily sort mixed-stream waste into the appropriate homogeneous categories. Everything that can’t be easily sorted should be required to be biodegradable.