Mark the door with a chalk pencil, at the level you intend to hang the top of the curtains. Measure and note the distance from the top of the door to the mark. Transfer that measurement to the left and right sides of the door. Using a yardstick as a straight edge, draw a straight line between the marks with a chalk pencil. Mark two points on the line, where you plan to install the outer hooks.
Measure and note the distance between the two marks, indicating the positions of the outer hooks. Count and note the number of grommets, button holes or loops at the top of the curtain, then subtract one. Divide the former (width) number by the latter (grommets, etc., minus one). The quotient tells you the width of the spaces between the hooks. Mark that distance with a chalk pencil on the yardstick.
Align the edge of the yardstick to the horizontal line on the door. Mark the positions of the screw-in hooks on the line, using the calculated distance between them or the marks on the yardstick.
Hold the tip of the awl on the first mark. Tap the awl with a mallet to pierce the door and to make an indentation about 1/4 inch deep. Working from one end of the line to the other, use the awl and mallet to make pilot hole at each mark. Screw one hook into each pilot hole.