Take a bowl and fill it with water and Aqualinos. These are such transparent water gel-balls, which are actually very hip in germany.
Fill the tealight holders with the coloured sand and put the tealight on top of it. You can take any other coloured stuff instead of the sand, like small drops, stones, whatever.
After that you put the tealight holders on top of the Aqualinos, so that the three create a big triangle. After that you can fill the space in between with a few shells.
Then you can bind the ribbon along the border of the bowl and end in a bow. Therefore it´s easier to take a bowl with a straight border.
That`s it. Place it on a table infront of your guests and they`ll be busy while you´re preparing the food =)