"Some simple guidelines to Wizardhood that have helped me live as long as I have.
One? Don't look like a wizard. In every combat training manual in every language (where I'm from at least) there's an idiom that amounts to "Kill the mage first". Before you start slinging spells, make them wonder if there even is a mage. Try to keep your staff simple, a quarterstaff is a versatile tool not necessarily belonging to a mage. If yours is ornate dress exactly as fancy as it is so it could be a simple walking stick. Simple staff? A leather jerkin and other simple clothing will server you well.
Two? Basic physical conditioning with an emphasis on cardio. You need to be able to keep up with a party, if you can't you'll probably die.
Three? Aim your first spell for any mages who don't follow these rules."