The instructions below will show you how to make a easily reopenable lid for a case. This principle can be applied to a wide variety of uses.
Step 1: Create a Hollow Container
Create a hollow container, with one side open.
Step 2: Create a Lid
Create a lid that fits perfectly on the case. Put a small rectangle on the edge of the lid. Make sure the rectangle is half the size of the width of the case. The rectangle has to be placed half the length of the with of the case from the side of the lid.
Step 3: Pressure Part
Create a round or other shape at the end of the rectangle. This shape is where the fingers will press when opening the lid. You can put a logo in this shape, for nice details.
Step 4: Making It Fit
Duplicate the lid and it's attachements and make it hollow. After doing that, you can place it against the case, as if you would close it.
Step 5: Finished!
The previous step will leave out the outlines of the lid, making it possible to perfectly place the lid into the case.
When pressing the two shapes, you can then pull out the lid. If the case is closed, it stays perfectly closed.