Each is 11 by 17 inches, printed on weatherproof vinyl with metal grommets for hanging. That size suits a group of two or three together on one wall, or a single piece in a narrow space between larger hangings — a single 11-by-17 alone on a big wall tends to look lost.
Cable ties or S-hooks through the corner grommets, fixed to the sukkah frame. Fasten all four corners rather than just the top so the print does not flap in the wind, which is what creates the tears around grommets over a few seasons.
Weatherproof vinyl is made for it — rain runs off without the ink running or the print warping. Let them dry before they come down at the end of Yom Tov, and they will be ready to go straight back up next year.
That is how these look best. Three at the same height in a row, or two above and one below, reads as a deliberate gallery rather than as decoration filling a gap. Keep the spacing between them even and roughly equal to a hand's width.