Gather sticks from a nearby wooded area. If you are unable to find sticks, you can buy bamboo sticks at most plant nurseries relatively cheaply. The number of sticks you need depends on the size you want the trellis to be. Sticks of any thickness will work, but they all should be the same length.
Lay half of the sticks down so they are running parallel. Space them about 6 inches apart. This will make up the height of the trellis.
Lay the remaining sticks on top of the other sticks so they make a checkerboard pattern. Space them out so that they are evenly spaced from top to bottom.
Put a zip tie wherever the sticks intersect. Wrap the zip ties diagonally across two sticks at a time and pull tight. Work around the edges first. You may want to use two zip ties on the edges for extra security. Cut the tails off the zip ties when finished putting them in place.
Lean the trellis against a wall or attach stakes to it with zip ties so that you can erect it in the middle of a garden.