Take an off-center part through hair from front to crown.
Section out 1-inch from front hairline, working through the back, across occipital. Apply Formula 1 to hairline and nape sections.
Starting just above nape section at occipital, take a criss-cross section from left to right, using the off-center part as a guide. Apply Formula 2. Use foils to separate each section.
Continuing towards front from back, take a criss-cross section from right to left. Apply Formula 3. Continue alternating the criss-cross sections with the respective formulas. Keep lines very straight to maximize color placement and to keep foils stationary.