Your jewelry should be the last thing you put on before leaving to avoid getting sprayed with perfume, hair spray, sunscreen or lotion.  And yeah, everyone should be wearing sunscreen now.  Don't wear jewelry when you may come in contact with cleaning or pool chemicals, pool, lake or ocean water, sweat or spray tan or hair dyes.

If you can, store your jewelry together, but a part. What that means is don't mix your metals, particularly oxidized metal from shiny silver.  Try to keep them in air tight plastic bags to help delay tarnishing.