What 5e variant/house rules do you play with that work?
I'll be DMing some more 5e soon and I want to take the opportunity to try some different ways of playing (I'll post my own suggestions as comments so they can start their own discussion threads). What alternate rules have you tried that you thought worked well? They can be larger changes to the game or little QoL tweaks (though if you can respond to the suggestion with "at this point just play [different game] instead" then that's probably more than what I'm looking for!)
Isn't trading down actions RAW? A Full Action can be used to perform an extra Bonus Action, a Reaction (out of turn action with triggering condition expressed to the DM), or a movement action.
For the potions, it's a step for each rarity, Normal is 10hp, greater is 20hp superior is 30hp. Makes sense because it's the same potion, why should it's effects vary from use to use.
I have allowed our bard to use its action to replace it as a bonus action a few times. Its usually used to grant inspiration and do his bonus action shove from telekinesis or use a bonus action spell with inspiration. It was common at the lower levels but stopped at higher levels since he has more options.