You could always put it to the test. In honor of the celeb-designer mecca that is New York Fashion Week, find out which dynamic duo you and your BFF channel the most. Hey, if you and your best bud ...

So, it's only right that the BFF duo had a super fun day together ... Tracy and Josh sang different Christmas carols, perfectly harmonizing with each other. "It was holiday time," Tracy wrote ...

That formula seems to have worked for eterna-buds and Friends co-stars Jennifer Aniston and Courteney Cox, who looked so in BFF love last night at a screening that we instantly went green with envy.

The Sweet Home Alabama actress added her own words of friendship to the post, writing in her Instagram caption, “Work just hits different with your bff 🫶 ... “Best duo ever ️ ...