Do you want an arrangement or a curtain? SORRY!
A swag is just a length of something draped between two or more fixings, so anything at all could do the job. The only limit is your own imagination!
Have fun and enjoy the journey.........
If you're looking for a floral swag this may help: https://homeguides.sfgate.com/make-floral-swag-front-door-93698.html
However, if it's a curtain swag this may help: https://homeguides.sfgate.com/cut-swag-curtains-61509.html
Hello, this should give you ideas, pick the flowers and greenery that you love and go for it!