They all have the same basic meaning and are all natural, but I would personally use each in a different context. 1) What you wear speaks volumes about who you are. This one feels slightly more negative or passive than the others and implies that "you" (the person in the clothes) is *unintentionally* indicating something about themselves. e.g. "His Adidas track suit spoke volumes about how familiar he was with the environment of an exclusive golf/country club." ... meaning "not very familiar" 2) What you wear makes a statement about who you are. This one feels like it has more intention and purpose about it. e.g. "Hillary Clinton wore a red suit to the summit in order to make a statement about her role in the global community"...meaning "a powerful role" 3) What you wear says it all about who you are. I think this one is on the neutral side of passive and seems to me to say more about the judgment of the observer than the intention (or not) of the wearer. It sort of implies "I know all about a person just by viewing their clothes" These comments are just how I would interpret the phases if used in conversation, others may have different responses. I'm Australian and I've found that we use English somewhat differently to other English-speaking places. :)

I agree with Kylie. The first sentence can have a negative tone, it's most definitely cautionary. The second one is a more neutral sentence, one that could be found in print. The first two are more formal than the last sentence. The differences are subtle, if you want to warn your readers, choose the first. However the first sentence seems a little cliche to me, it's been used a lot already. For something neutral and formal, choose the second. If you want to sound informal and youthful chose the last sentence. The last sentence is written the way a native speaker would 'speak', this makes it ok for some uses, not ok for others. If you are writing an essay, I would choose the second or the first. Hope this helps.

The first and second sentences sound better than the last. "What you wear says a lot about who you are" would sound more natural to me.