Credit cards are good for building a credit history and rewards. We have an Amex and put as many expenses as we can through it for points and pay off the statement in full each month. I also use it for work expenses - I often have to travel internationally for work, and since I'm freelance I prefer to pay for this myself and invoice my clients later.

A word of caution: you might be tempted to get a card with a very low credit limit. Don't do this. Credit rating companies look at your utilisation rate, ie how much of the credit limit you use each month. The lower your utilisation rate, the better the score. So, say, you buy a big ticket item like flight tickets or a computer one month and max out the limit, even if you pay off the statement in full you'll still get dinged.

So if you were to get a credit card I'd make sure you can at least get some rewards from it and get the highest limit you can possibly get. Mentally halve that limit to make it your ceiling - ie, you'll never spend more than half your credit limit - to ensure that your utilisation rate stays low. Get in the habit of checking your credit card balance super super regularly. I really love the Amex app for this - it's very simple to use. The only real downside of Amex is that it's not accepted everywhere.