How do you do this: How to best carve out a wooden clamp for picture frames?

OPTIONS:
- Take two sticks of wood of desired thickness. cut them into equal length, while chopping away a diagonal piece from one end of both pieces at an angle of 45 degrees. Tie both the piece using a strong string.
- Take a square slice of wood with required thickness. cut away a smaller square sized piece from it, from the interior, so that the remaining piece makes a sturdy good clamp.
Take a square slice of wood with required thickness. cut away a smaller square sized piece from it, from the interior, so that the remaining piece makes a sturdy good clamp.