This penny mosaic was inspired by a "three hearts" painting I saw on an episode of Sex and the City (see second picture). Wanting to put my own spin on the recreation, I decided to forgo the standard paint-and-brush approach and instead use pennies. I also chose to go with a vertical rendition of the original, but feel free to follow your own "three hearts" desire.

Step 1: Gather Materials

What you'll need:

Poster board and frame
Pennies
Glue
Ruler
Pencil

Step 2: Sort the Pennies

Gather the pennies you’ve collected over time or acquired from the bank. Based on shade, sort them into three piles: (1) shiny and bright, (2) dull and dark, and (3) those falling in between shiny/bright and dull/dark.
I chose to place all my pennies heads up--for good luck--so I really only needed to determine the shade on one side of the coin.
You'll be using Piles 1 and 2 for this project.
It took me about 18 rolls (900 pennies) to get enough shiny pennies. The ones I don't use I plan on hauling to a Coinstar or re-rolling and depositing in the bank.

Step 3: Prep the Board

Using your ruler and pencil, divide the board into three even sections/squares.

Step 4: Place a Heart in Each Section

Create a heart shape using the pennies.
Place (but do not glue) a heart in the middle of each section.
Alternate shiny and dull hearts.

Step 5: Fill in the Backgrounds

For sections with a dark/dull heart, fill in the background with shiny pennies. For sections with a bright/shiny heart, fill in the background with dull/dark pennies.
Remember, no gluing yet.

Step 6: Glue Pennies in Place

Make sure the hearts line up with each other and that there aren't any distracting/rogue pennies in the backgrounds.
Once you're satisfied, glue each penny in its place.