I'll suggest you discuss how to sent before confirming a swap though. I am only using registered mail on very rare occasions, due to the cost, but if my swap partner want me to sent registered after confirming…
Just saying it's good to figure out how to sent and agree on who sent first or at the same time, before confirming 😅
I have a soft spot for origami paper cranes.
Read or watch about "Sadako Sasaki and the Thousand Paper Cranes".
Spread a little peace and happiness wherever you go :)