Fighting
The base is the strong part: it takes three hits to open a hole there, but after that every hit goes straight through until it's patched. A sniper's base shot breaks through at once and is a sure kill. On a wine glass the base is the bottom of the bowl, and a shot to the stem just snaps it off.
Every drink has a default gun, but you can pick any primary and secondary for it in the menu. Heavy guns slow you down, so press X to swap to your secondary and run faster. Machine guns switch between auto, burst and single with B.
Up close, press F to lunge and bonk. It breaks the drink where you aim, like a shot, and from behind it does double damage. Press R next to a dropped gun to take it.
You can't aim while reloading. Sprint cancels a reload, but in its last moments sprint finishes it early instead.