First get a cup like the one on the right then get a smaller cup then get foil that you bake with
Step 2: Put water in the cup
First go to the sink and put the water in the big cup fill it 1/3 or test it out by putting the smaller cup in the middle of the big cup. Be careful you'll have to line up the small cup exactly in the middle in the big cup.
Step 3: Put foil on the cup
Hold the small cup and with the other hand get the foil and put it on the cup. Cover it and see by the foil marks if it is lined up
Step 4: Put it in the freezer
Ten with the foil on top tightly bring it to the freezer. Check on it and when all of the parts are frozen bring it out. Then take the foil off. Take the smaller cup out carefully. Then you may notice that the bottom part is thin and may crack. To fix it go to the sink and put some watter til it fills 1/4 of the ice. Put it in the freezer again.
Step 5: Take the cup out and Enjoy!
After the bottom part is frozen go to the sink. Here comes the tricky part. Slowly while the water is on get the cup with the ice and put the water around it. This may take a few moments. After you have done it and think that you can take it out with your fingers and let the pressure go out and wala! You'll have your ice cup! Put some of your favorite drinks in and enjoy the heat!
Below is a picture of the finished product.