Thomas More wore a “hair shirt” underneath his fancy garb. The discomfort of the shirt reminded him to not be enamored with all the fancy trappings of man.
Though Christ fully atoned for our sins and we hardly need a “hair shirt,” there are warnings in Scripture to not be enamored with the various ways the world seduces us.
Two passages in this regard which have meant a lot to me over the years are Isa. 2 and Prov. 23:1-3.
You may not have anything approximating a “hair shirt,” but what truths in Scripture help you keep your eyes on Christ and not the enticements of the world?