Box 1: rubber legs/small streamers/larger attractor nymphs; Box 2: small nymphs (PTs, czech style, PT variations, attractor nymphs)/attractors (various worms, scuds); Box 3: (small box) caddis variations, mostly pupae; Box 4: streamers; Box 5 (small box): midges, assorted colors, styles, sizes;
I pack a lot of choices and usually pre-tie my tandem nymph rigs, so I just change the tandem rig if it's real slow, or just the trailer fly.
A lot depends on what I want to do that day, streamers mostly, just in the morning, or, nymph all day. When it warms up more, then terrestrials come in.