I like to layer multiple die cut designs by stacking them on top of each other using foam tape.
MemoryDex cards are a great way to show a collection. To make ephemera pop out more, I like to use foam tape to make them stand out.
To make your die cuts have more dimension, cut multiples and then glue them on top of each other to create better depth.
To make your project more fun, try cutting up some paper to create multiple layers of fringe.
To make your sticker or ephemera have a 3d effect, tape the middle down and then roll the edges upward. Thickers are a great and easy way to add dimension without adding too much height.