paper or plastic cups whatever you choose is up to you.
straws or tubes or pipes or whatever.
a thumbtack or a drill if you use plastic cups.
Step 1: Poking holes.
Take the pencil and poke holes near the bottom of the cup so that the straw will fit in the hole snug, repeat with the other cup.
Step 3: Putting it together.
Put the straw in the holes in the cups so that they are connected to each other. Now fill one cup with water. Place it where you want it and the water will come out of the holes in the straw watering the plants.