Hour Glass
This is simple and easy tutorial for and hour glass or sand timer.
Supplies
2 Water Bottles
Drill (or Hole Puncher)
Tape (preferably Duck Tape or a strong tape)
Bottles
Fill one water bottle with sand and drill holes into the bottle caps. You can do this with a drill.
Combine
Then go ahead and tape the bottles together. Be generous with it so it won't fall apart.
Extra
You can always add more and customize. Choose material that fit your preferences. And elaborate. This is just a simple and easy hour glass.