Select a theme to focus on. Depending on how much money you're willing to spend on decorating, you can choose essentially any motif -- such as a landscape, particular band, solo artist or instrument -- and run with it.
Use masking or electrical tape to attach any paper materials to the turntable. Glue is best avoided in case you eventually change your mind and want to remove the decorations.
To give the turntable a sleek, clean look, ensure that every inch of free space of the instrument is covered.