Help me build a small raspberry trellis
Backstory: I planted a couple of 1-gallon potted Dorman Red raspberries in a raised bed this spring. I didn't take good care of them, so weeds took over and one died. About a month ago I dug up the remaining raspberry (including 2 or 3 suckers) and put them in pots while I cleared the bed.
Anyway, I've reshaped the bed to make it easier to take care of. It's about 10 inches high, 4 feet wide, and 9 feet long.
I'd like to make a simple yet sturdy trellis to tie the canes to. I would appreciate any tips, including what kind of posts to buy and how to tie the wire/twine to the posts.