Make sure the plastic bag is airtight so that your book doesn’t pick up any additional moisture from the freezer.
Drying the book beforehand will make sure the pages don’t stick together. If your book has any mold on the pages, gently brush off any topical mold spores with a clean cloth and then set your book in the sun to dry out.
Wet or water damaged books are prone to falling apart, so it’s important to be careful when you handle them.
You can also set up a dehumidifier to dry out the pages even more, if you have one.
Plywood is a great wood to use for sandwiching your book, since it’s pretty thin.
Try to keep your book out of the direct sunlight so that it doesn’t get too hot.
If your book is still wavy, you can try leaving it pressed for longer.
If you don’t have a spray bottle, use a clean paint brush to dab water onto the book pages instead.
If you have an ironing board, you can set that up as well. Otherwise, you can make a small workstation on your table or counter top.
Don’t leave your iron on top of the book pages for too long, or you could burn your book.