Crates

Crates are the entire reason that cosmetics and war paints are created with the exception of crafting, but crafting only allows specific hats and crafting cannot be unusual.

Unboxing

Crates have a variety of different cosmetics, some being exclusive to that crate. For example, there are some cosmetics from the Rainy Day collection that can only be obtained by unboxing that set. Now, most people argue against opening crates, especially if you want a specific cosmetic or unusual effect. Remember, crate keys cost about $2.49 USD each before taxes and fees, not including the crates.

What to unbox

Again, I would recommend against unboxing at all, because getting a strange is a 10% chance, an unusual is 0.6% chance, and a strange unusual is 0.06% chance (one tenth of the odds of an unusual). If you ever do unbox, DO NOT USE MANN. CO CRATES, because they only really give normal weapons, but almost never are worth unboxing. With regular crates, you at least get regular cosmetics or war paints, but Mann. Co crates are quite useless, relatively speaking.