Clothing as a symbol of status pops up quite a bit in the play. It often tells us about a person’s station in life. Interestingly, the play’s characters change their stances on love and their reputations as easily as if they were changing clothes, like Claudio vacillating on his love for Hero, or Hero’s reputation being clean, stained, and then clean again. When Beatrice teases Don Pedro about how she won’t take him for a husband, she says she’d need a less fancy man, as Don Pedro is too fine to wear on working days. Dogberry, who is hyperconscious of his status, and tries to prove he’s a gentleman by bringing up the fact that he has two gowns, and fine things to make himself handsome.
Appearance is everything here – Benedick’s unkempt and mixed up clothing is what exposes him as a lovesick man; though he’s usually in the habit of a soldier. Finally in one of the most crucial and revealing conversations in the play – when Borachio comes clean to Conrade about the plot against Hero – there’s a conversation about fashion, which Conrade claims "wears out more apparel than the man." The idea is that fashions change too quickly, and this encourages otherwise reasonable men to get rid of perfectly good clothes. This capriciousness describes the fashion, but it also describes love in the play, as characters fall in and out of love and are rendered foolish by it. The point is love is a fashion, and people change love like they change clothes.
Horns show up consistently in the play as a symbol of marriage (and the corollary notion of a husband being whipped in marriage). Remember, cuckolds were men who were married to unfaithful wives, and were generally long-suffering. Horns are an interesting symbol, because while they’re used in this context to denote a whipped guy, they’re also a thing of wild beasts. Don Pedro jokes about the "savage bull" with horns at the beginning of the play when Benedick refuses to marry, and again when Benedick has chosen to marry after all. The inevitable horns that come with marriage (remember Beatrice jokes that if God sent her a man, He’d have to send horns too) represents marriage as a process by which wild animals are tamed.
Horns are joked about throughout the play, but over the course of the action they become less fearsome as the characters come around to viewing horns as an ornament of love. At the end of the play, Claudio promises that Benedick will have horns, but they’ll be gold-tipped, like Jove’s horns were during his lusty conquest of Europa. Horns are thus a thing of wild animals, but as the characters learn to accept and be excited about marriage, they come to symbolize the bawdy pleasantries of marriage.
The title of the play, given that "nothing" was pronounced as "noting" in Shakespeare’s day, clues us in to the fact that noting is central to all of the action. Noting is a motif throughout the entire play in the form of observation (when Claudio asks if Benedick noted Hero, when Friar Francis says he’s been busy noting Hero at the wedding, etc.), through music (as Benedick jokes about sheep’s guts as strings on an instrument, when Balthasar plays his notes, etc.), and also through written notes (like the letters that ultimately reveal Benedick and Beatrice’s love at the end of the play).
Ultimately, the play revolves around misnoting – the problem of people wrongly interpreting what another person does or says. Benedick and Beatrice are manipulated into noting false conversations about their mutual love, and Don John sets up Claudio and Don Pedro to wrongly observe (or misnote) Hero’s loyalty. The play constantly points out the difficulty of observing correctly, as observation is always subject to interpretation, and interpretation is often wrong. This doesn’t mean that misnoting can’t have good outcomes – after all, Beatrice and Benedick do get together as a result of it – but Shakespeare is essentially laughing at the follies that result from misnoting.