Common Menswear Mistakes & How to Avoid Them

Whether you’re suiting up for an important business meeting, a wedding, or simply elevating your everyday style, a well-tailored outfit does more than look good — it tells the world you mean business. But shopping for a suit, especially online, can be tricky. There are a myriad of menswear mistakes that are easy to make, but fear not, in this article, we’re going to run through the top mistakes men (and women) often make when purchasing a suit. Read on to find out how to get it right. 

Choosing the Wrong Fit

One of the most common mistakes people make when buying a suit is choosing the wrong size. A suit that is too large can make the outfit look sloppy, while a suit that is too tight can feel uncomfortable and restrict movement. The fit of the suit can affect the size, so it’s crucial to know the type of fit you are buying. All of our suits are cut to a slim tailored fit. As a general rule of thumb, most men’s blazer sizes are 6 inches higher than their waist sizes. For example, if your trouser waist size is 34”, then your blazer size is likely to be 40.

How to Avoid It:
✔ Know your measurements — chest, waist, shoulder and inseam are key.
✔ If in doubt, size up and have your suit tailored to fit your body shape.
✔ Use size predictor tools like our “What’s My Size” tool to help determine your size.

Mixing Formal and Casual the Wrong Way

One common mistake in menswear is incorrectly mixing formal and casual pieces. A suit can be paired effectively with casual items if you select the right styles. For instance, a plain two-piece suit looks great when worn with a simple white t-shirt and clean, crisp trainers. Similarly, a blazer pairs well with pintuck joggers and a button-up polo shirt. The key is to keep the look simple, aim for a cohesive colour palette, and choose quality basics.

How to Avoid It:
✔ Match tailoring with appropriate simple basics
✔ Opt for a cohesive, complementary colour palette 

Neglecting Minor Tailoring Adjustments

One of the most common mistakes people often make when buying a suit is thinking it will fit their body perfectly. Whilst this is the case for some, more often than not, most would benefit from tweaks to make it perfect for their body shape. Adjusting the sleeve length, taking up the trouser hem or tapering the waist of the blazer can hugely transform a suit from good to great. 

How to Avoid It:
✔ Budget a little extra for alterations.
✔ Check jacket sleeve length: your shirt cuff should show just slightly.
✔ The trouser hem should just skim the top of your show

Underestimating the Power of Accessories

Even the best-fitting suit can look unfinished without the proper accessories. Simple accessories can transform a look. When choosing accessories, it’s important to consider the occasion. If you’re choosing a tie for the office, then generally a simple plain or striped tie will be the best bet. If you’re selecting a tie or pocket square for a wedding or semi-formal event, then you have the freedom to be a little more experimental. 

How to Avoid It:
✔ Match proportions — slim ties with slim lapels, traditional leather shoes with formal suits.
✔ Keep accessories minimal and purposeful.

 ✔ Never match your pocket square with your neckwear. They should complement each other subtly. 

Ordering a Suit Online Without Getting It Wrong

Ordering a suit online is convenient, but without trying it on first, small fit issues can easily be overlooked. The most common mistakes come from guessing sizes, misunderstanding fit types, or expecting a perfect fit straight out of the box. A well-made suit is designed to be refined through tailoring, not worn unchanged.

How to Avoid It:
✔ Take accurate measurements and always check the size guide rather than relying on previous purchases.
✔ Understand the fit — slim, tailored, or regular will sit differently on the body.
✔ Prioritise shoulder fit, as this is the hardest area to alter.
✔ Expect minor adjustments to sleeve and trouser length for a truly polished finish.

At Marc Darcy, our award-winning heritage in British menswear shows that the difference between looking dressed and looking stylish is in the details. Whether you choose a timeless wedding suit or a statement blazer, attention to fit, tailoring knowledge, and thoughtful adjustments will ensure you always look your best.