I made this cup from a plastic bottle that you would normally drink from. Hope you enjoy!

Step 1: Supplies

You will need:

Tape (Make sure it is a good brand!)
A plastic water bottle
Scissors
A marker

Step 2: Marking the Bottle

Take a marker (any color) and draw a line around the bottom of the bottle (shown in picture above).

Step 3: Cutting

After you have drawn the line take some scissors and cut on the line and don't worry if it's not a clean cut, just make sure it is kinda straight.

Step 4: Adding Tape

To make sure that your lip won't get cut take some tape and put it around the edges.

Step 5: Adding a Handle (optional)

First make sure you have an extra piece of plastic lying around. Take that piece and part of of it in the cup and add tape to it (A LOT of tape). Then take the other side of it and tape it near the bottom of the cup (make sure it looks like a cup with a handle on it before completely securing it to the cup)