Here is a lovely collection of free templates I’ve found online, use them to collect and organize your seeds and to give those you’ve harvested  from your garden as gifts. These envelopes are also popular to use as wedding and baby shower favors (just print & fill with treats). The templates are pretty much cut & glue versions but there is an origami tutorial listed too, also note that a few of the pages listed below offer more than one design (I’ve noted those in the descriptions).
Scrapbook Paper : Shows you how to make packets with pretty scrapbook paper. Includes free pdf downloads for blank template & stickers.
All-Occasion : Peas aren’t what you’re looking for? No worries, you’ll find another dozen designs to download!
DIY Project : Pattern design is in black & white, print on colored paper of your choice. Free pdf download.
Assorted : A few different designs. These are editable so you can type what you want on them before printing.
Origami Directions : Instructions on how to fold your own origami seed packets, no glue necessary!
All Kinds : Different designs to choose from, can be used for seed packets, coin envelopes, etc.
Wraps : Four different colored wraps per sheet (free pdf download), features a “To” and “From” section on the back for gift-giving.
Glassine Envelopes : Print assorted labels for pumpkins, squash and gourds then apply to glassine envelopes.