Get the lume you want. Both RA and I use a water base acrylic glow paint, and thin it a bit further with water. Then take a picture of your dial or off the net and print up a few. Then practice on them. I've used everything imaginable to apply, from toothpicks to oilers, and tiny artists brush. I'm too old and shaky to make a straight line. Fortunately, many of the old gen gilt dials I have seen were done by someone with the same affliction! For me, a nib (the calligraphy pen) works best. It gives me the control and comfort I need at my advanced age! I use that on the 6 and 9 straight markers, and the coronet at 12. For the hour markers on gilt dials I use a round toothpick, or one of those skinny bamboo skewers for shish-ka-bobs, flatten the tip to about the size of the marker inside the surround, lightly dip in the lume and lightly touch as close to center as I can. A little practice makes almost a perfect circle every time.
Be brave! If you think of something that makes sense to you, try it. If it works tell the rest of us! If it doesn't work tell us anyway so we don't!