Find the best fruit of the plant you want to collect seeds and don't eat it.
Separate the seeds from their fruits, then clean the seeds and dry them
under a dark, ventilated shed as dirt can encourage bacteria or fungus to grow which will rot the seed.
Use paper bags rather than plastic bags to store the seeds.
Put the paper bags in clean, dry jars with lids and maintain in a cool and dark place such as your fridge.
On the package, attach seed details such as plant name, type, date of collection, date of expire, and colour.