Measure the area you want the canopy to protect. Write down the dimensions on a piece of paper to take to the store with you.
Select an appropriate fabric. If you want the canopy to take camping for the weekend, pick a material -- such as light canvas -- that will stand up to the elements and be easy to pack. Another option is to buy a drop sheet that already has prepunched holes.
Gauge which sorts of poles will work best. If this is a rough and ready DIY canopy, check your workshop to see if you have some materials -- such as leftover doweling -- that can be used for poles. If not, head for the lumber yard and calculate how heavy a pole you need to support the weight of the canopy. Bamboo gives you a finished look, so it is worth considering.
Take a knife and whittle away the bottom of the poles to make them easier to stick in the ground.
Punch a hole in fabric if it is heavy and won’t ravel -- such as canvas -- or cut a small hole and stitch it like a buttonhole to keep it from fraying for lighter material.
Run a nail through the hole in the fabric. This provides the anchor for the fabric, so the heavier the material, the larger a nail or screw you will need. Tie a piece of cord over the top of the fabric and run it like a guy-wire to a tent peg to stabilize the poles.