First , don't blow your budget on new clubs. Clubs are the most important pieces of equipment in your bag, but no club exists that will dramatically change your game overnight. It's better to invest in clubs you can afford. Most irons are made from this process, so choosing is easy. As far as shafts, it isn't going to make a great deal of difference whether you play steel or graphite.
Steel is often less expensive, but either material performs beautifully in the right hands.
Second , ask the same golf professional who's instructing you to evaluate your golf equipment. He or she can determine in an instant if the shafts on your clubs are appropriate for your swing speed. If you happen to be carrying a set of forged blades, and you're either new to the game or usually don't break 90, you may be advised to get new irons. Confidence is what you're after. In order to feel good about a particular shot, you have to like the club you're swinging.