Anything flat that you can cut and engrave will work fine. 3mm basswood plywood is a good basic material, but you can try acrylic or other materials.

[Note: the dish in the cover picture is 3D printed and not part of this project. That design is "Stackable Bowl Tray - Curvy Waves 03" on makerworld.com.]

Adjust the settings appropriate to your machine for engraving and cutting. If you're painting your hearts, set the engraving a little deeper than the default to make it easier to paint the lettering. Black objects are engrave, red lines are cut.

You can scale the hearts bigger or smaller as you prefer, but be aware of choking hazards, especially since these look like candy!

There are two canvases with 30 hearts each. Cut them both, or just pick your favorite sayings and set the rest to no output.

The hearts will look great unpainted, but to really make them pop, slap on a little paint. Some ideas:

1. Spray (or brush) primer onto the hearts. (Unfinished wood will otherwise suck up your paint and require many many coats to finish. Optionally, you also can sand the primed hearts before painting for a nice smooth finish.)
2. Spray (or brush) on paint in different pastel colors (this project used 6 colors). It may take a few coats to get an even color. 
3. When dry, color in the lettering with a red paint pen (or brush).
   - Ohuhu (available on Amazon) makes some great little acrylic paint pens with thin and thick tips on each pen. The thin tip works great for the lettering--just be sure to drag down with the pen since pushing up can splatter the paint as it catches on the grain in the engraving.
4. Spray a matte clear coat over the whole shebang to lock in the colors and give all of the hearts a consistent appearance (helpful if you have a mishmash of matte, satin, and gloss paint colors… it'll all turn out matte with the clear coat!).

Display in a candy dish or give away as little Valentine's gifts. Happy Valentine's Day! ❤️