Spoon it on. Hardest part of the spit shine is having enough polish to fill the leather grain.
Get a half teaspoon spoon. Put a thick coat of polish on the toe of the boot. Heat the bottom of the spoon with a lighter. Best way to judge if you have the spoon at the right temp is to put a speck of polish in the spoon. When it melts, the spoon is right.
Using the rounded bottom of the spoon, rub spoon on toe of boot, melting the polish into the grain. Allow polish to dry and cool, then buff with a soft brush.
Repeat this a few times until the grain is filled. Then use a cotton ball or your favorite polish rag, a little water or spit, a dab of shoe polish, and polish the toe. You will get a mirror finish.
This technique will work on the other parts of the shoe or boot.
I have, over the course of a 20 year USAF carear in Security Police, tried most every brand of polish. Kewi works best.