Use the ellipse tool to draw a circle and apply the new brush to it. Draw three small circles with the ellipse tool (hold shift to constrain the ellipse to a circle) and fill with a red and white radial gradient. Adjust the gradient as needed, group the berries and make copies by option/alt + dragging. Add them to the wreath. Use the inner glow effect if you wish (Effect > Stylize > Inner Glow) to add more shading. Select all pieces and group.
That was easy, wasn't it? Happy Holidays!