Use the convex rounded side of the Derma Wax Spatula to take the Eyebrow Plastic out of the jar. By scraping it out, you already make the texture a bit flexible.

Thin eyebrows: apply Eyebrow Plastic with the convex rounded side of the spatula in the direction of the eyebrow hairs, ensuring that no hairs stick out. Smooth the edges flat so that grease and moisture can not get underneath.
Thick eyebrows: comb the eyebrows against the direction of the hairs with an eyebrow brush. Then use the brush to apply Eyebrow Plastic against the direction of the hairs, after which the brush can be used to smooth the hairs in the natural direction. Eyebrow Plastic can then be applied as per the technique for thin eyebrows.