Step 1: Assemble Materials
Garden trellis: these are available at home improvement and garden stores. The ones I used were 36" on a side, made from 1x1 strips. They had 2 longer strips in the center for driving into the ground; cut these off.
S-hooks: get lots. The ones I use are made of 1/8" steel. Take your trellis to the hook department and make sure that they are the right size to fit over the trellis slats. They might need just a little bending
Mounting screws: Long enough to go through 3/4" strip and 1/2" drywall... 2" are a good choice. Also may want some drywall screws to add extra stabilizing support for parts that aren't over studs.
Sandpaper: Straight from the store, this wood is pretty rough. I gave it a quick touch with 160 grit to take off the splinters. You could finish or paint it if you like
Tools: Drill, stud-finder, screwdriver, saw, vice-grips or other sturdy pliers
Step 2: Locate and Hang
Drill pilot holes into the stud and pre-drill the holes in the trellis, otherwise you'll split the thin strips.
Attach the vertical bars to the wall. This will leave the horizontal bars 3/4" of an inch away from the wall so you can slip the hooks over.