A cool way of displaying leaderboards is by using armorstands of skulls on top of them. LeaderHeads makes it easy to do this by offering a command to create an armorstand on top of a sign.
Simply set up a sign first and then use the command
/leaderheads armorstand <small>/<big> to create a small or a big armorstand. Make sure that you're looking directly at the leaderboard sign when executing this command. The skull of the armorstand will be updated when the leaderboard refreshes. Please take in mind that the armorstands are not protected by LeaderHeads so make sure to set up a safe region for them.
You can use a tool like this one to customize the appearance of your armorstand.
To show a nametag above the armorstand, follow this holograms tutorial and make sure to place the hologram directly above the armorstand.