Cut your soap into the amount of cubes you need. They are pre-scored into squares in the package, so they are fairly easy to cut up with a sharp knife. I like to lay them on the molds to help guesstimate how many I need, especially because I have several sizes of silicone molds and each is a little different. It is best to figure at least one more than you think you will need.
Place the soap squares into a double boiler, and heat over medium until fully melted (alternatively, you can place a glass bowl or measuring cup into a pan of water). Stir frequently until it's very fluid with no lumps and easy to stir, then add your almond oil to the melted soap and stir to blend.
Once it's fluid and removed from the heat, stir in your essential oils.
Slowly pour your soap mixture into your molds, leaving a slight space at the top to add the spearmint leaves.
Once you have it all poured, get a thick pinch of spearmint in your fingers and sprinkle it across the top of the soap bars until they are covered all the way evenly. Then, gently press the leaves down into the soap just enough to make them stick, as if it’s glue underneath them, but not totally covering them so it will dry with the true color of the leaves showing. Keep the soap sitting out at room temperature for 1-2 hours or until completely cool. If you are making large soap bars, it will likely take longer. To be sure they're cool, feel the bottom center of each mold.
Once they are completely cooled, carefully pop them out of the molds. Bend back one corner of the mold with one hand and press on the back center of the bar with the other and that should do it. If they are still warm they will not come out easily.
To store your sinus relief soap bars, use cute little bags with ties to secure, or put in a glass jar.