As a noun:
* The border between Mexico and the United States is heavily guarded.
* She drew a border around the picture with a black pen.
* The garden was surrounded by a hedge that served as a natural border.
* The old town had a picturesque border of cobblestone streets.
As a verb:
* The gardener carefully bordered the flowerbed with stones.
* The government is working to border the refugee camps with barbed wire.
* The artist bordered the canvas with a delicate gold trim.
As an adjective:
* The border region is known for its diverse culture.
* The border collie is a very intelligent dog breed.
* We stayed in a border town, so we could easily cross into the neighboring country.
The best way to use "border" in a sentence depends on the context and the specific meaning you want to convey.