This one (ca. 1935-1939) gave garden hints like how to sow small seeds.
The seed sowing advice on the card in part reads:
...The beginner will find the work easier if a small hole is made in one corner of the seed packet through which only a few seeds can fall at a time...
There is even a card demonstrating how to sow small seeds by submerging the pot in water, instead of sprinkling water from the top on your seeds which will cause them to spill out.
You can see some of these beautiful gardening related cards here, the images in the post are from the NYPL Digital Gallery.