Well, I don't know exactly what you mean by the easiest method. I only know of two ways to draw a symetrical 5-pt star. One way, if you have a protracter, is to start drawing intersecting line from a dot, at 72 degrees each. Put your compass into the dot with one point, and draw a circle in the Diameter that you want your Insignia to be, your time frame makes it easy,,,,no border to worry about, the star's tips touch the outer edge of your circle. Then connect every other point inside of your circle. The pentagon inside of that star is the diameter of your Red Dot. (the other way I haven't done since math class,,,,,it just involves swinging a compass to cut the circle into five equal-sized arcs)
Easiest way,,,,,,,,no matter how much you dislike someone's decals,,,,,if the points of the star are equidistant, that is a pattern for your mask. (they mess up the colors or the bar proportions, the star is still a star, the circle is still a circle, etc) Make one "star mask" for each Insignia. Make one "circle mask" for each as well. and make one "open dot mask" lay down a Circle Mask, paint with White inside the circle. Lay down your star mask, and spray the Blue. Peel off the masks whenever you usually do during your "spray, dry, and unmask" routine. Lay the Dot Mask over your White Star, applying more tape around it to eliminate overspray on your star and circle. Spray Red dot.
you should have a Red dot Insignia, made with masks, just like all the real aircraft,,,,,that is, just like all the real aircraft that didn't have Insignia Decals in real life.
Rex
Your three masks should look like a large mask with a hole in the middle,,,,,,,a solid star mask,,,,,, and a small mask with a hole in the middle