Many young people are preparing to enter the full-time workforce. While this transition into adulthood has many challenges, one that may not be so obvious is building your new work wardrobe. As an experienced 9-to-5er, I’ve been able to develop a solid array of office wear; however, even the most veteran of employees can make an outfit mistake from time to time. So, for those just entering the workforce, and the old pros in need of a refresher, here are some common office outfit mistakes and how to avoid them.

For the newly minted grad starting her career, the transition from sweatpants to suits can physically feel quite jarring. Many younger, ambitious professionals fall into the trap of overdressing and looking too stuffy in business clothing. While you want to look professional, you don’t want to age yourself inadvertently. It’s a subtle line to walk between the adage of dressing for the job you want, versus looking like you’re playing dress-up in your mom’s closet. To find that balance, and dress your age in a good way, mix in casual basics with your workwear. Pair a basic white, gray, or black tee with your blazers and trousers. Swap out heels for menswear-inspired loafers, and don’t forget to utilize jewelry to bring your personality into your workwear.

On the flip side, if you’re a mid-career or senior professional, don’t let your office apparel become stale. Learn how to incorporate trends into your professional attire. My favorite of-the-moment fashion is athleisure, which is a mix of sportswear and loungewear for every day. While hoodies and logo tees are not appropriate for most offices, you can still have sporty pieces as part of your business look. The trick is to pair tailored sportswear with more professional items so as not to appear too casual.

Speaking of tailored, unless you have a bespoke suit, chances are, your workwear could use a bit of modification for a better fit. Taking in seams, hemming trousers, moving buttons, or adjusting sleeve lengths are all easy alterations for a tailor/seamstress. These adjustments instantly add polish, and make an ensemble feel more put together and professional.

Above, I suggested opting for flats as opposed to heels. However, heels are not the enemy. The mistake most ladies make is not finding styles that are actually comfortable. Trust me; they are out there. In general, lower chunkier styles are the best for work. Dr. Scholls and G. H. Bass have great options for comfortable heels both in boots and pumps. I’m also a fan of Aldo for block heels and wedges.

Of course, comfortable, higher-quality heels tend to have higher price tags than shoes from big box stores. But, when it comes to your career opt, when you can afford to, for investment pieces that will see you through many years of your professional life, versus fast-fashion items that won’t hold up over time. Picking “forever” pieces that will last more than a season without falling apart actually saves money in the long run. Again, this is your career, and it will pay off to spend a bit more on workwear than you will on more casual clothing.

Lastly, don’t be afraid to be creative with your office outfits. Play around with mixing and matching those investment pieces with basics and trendier items for a personalized approach to your professional look. This creativity works best the night before. Morning can be quite a rush, so try to put outfits together in advance.

Good luck to everyone starting out in the workforce here in the coming months. For the veteran staffers out there, don’t be afraid to refresh your professional style!