It’s important to use lint-free rags when wiping on and wiping off oil and wiping-varnish finishes. If a rag contains any lint, it will hang up on wood grain and stick in the finish. Many stores and mail-order catalogues carry lint-free cloth.
You can also use old rags from around the house, but T-shirt-type material is seldom lint free.
I often use durable paper towels from home centers or auto-supply stores. These paper towels come in boxes or rolls and are white or blue in color. As long as I change to a fresh towel once in a while on large projects, I don’t experience lint problems.
If some lint does stick in the finish, sand it out with fine sandpaper. Then apply at least one more coat of finish.