For me (and many others, I'm sure) it's different from day to night.
For daytime use, I have mine loaded with the essentials from shades, to a perfume roller (genius creation, those little things!).
I try to pack a little lighter for nighttime.
Opting for no wallet, and makeup taking up most of the space in my purse.
To save a smidge of room, I'll pre-apply blush to my brush so I don't have to take the whole kit and caboodle with me.
What are your essentials for day and night?