Collocations for packet - noun

empty
cereal, cigarette (cigarette pack in AmE), cornflake, crisp (all BrE)
ketchup, mustard, sugar (all AmE)
seed
pay, wage (both BrE)
a weekly pay packet (= wage) of £200

math (= work to do in the the holiday/vacation)
My kids have summer math packets from their schools.

open

contain sth
a packet containing seeds

soup

on a/the packet
Follow the instructions on the packet.

packet of
a packet of crisps (BrE)
a packet of sugar (AmE)