The first mistake is: “just in case, I will wear something heavier because it might be cool”. A summer wedding rarely ends in cold in the sense that you need a heavy fabric. Usually it is the opposite: you get hot in the blazer during congratulations, then while dancing, and finally on the way to the car. If you are worried about a cooler evening, it is better to choose a sensible outer layer for travelling, rather than wearing a heavy outfit from the morning.
The second mistake is too much contrast in a mixed look. A navy blazer with very light trousers can look great, but only if you combine them consciously: the right shoes, belt, shirt and accessories. If you add a bold tie pattern on top, it turns into chaos. In those situations, it is better to calm the look with one solid element, for example a tie in a single colour.
The third mistake is sizing. A blazer that is too tight in the shoulders will ride up when you reach your arms out to dance, and one that is too wide will make the silhouette look heavier. Trousers that are too long will break on the shoe and bunch at the ankle, which is even more visible in lighter summer fabrics. That is why tailoring alterations matter so much. In Albione showrooms in Poland, including Warsaw, Poznań, Wrocław, Kraków and Gdańsk, you can have pieces adjusted on site, which is often the difference between “fine” and “really good”.
The fourth mistake is more subtle: thoughtless accessories. A tie that is too wide in a light summer outfit looks heavy. A belt that is too shiny can pull attention away from the look as a whole. And socks? At a wedding, it is a detail you see when you sit down and when you dance. It is worth having a pair that matches your trousers rather than being random. At Albione you will also find Skarpety, which makes it easier to finish the look without running around several shops.
If you want to avoid the “my suit looks like it has been through a battle” problem after the wedding, it helps to know how to store and refresh it. Do not throw your blazer over a chair when you get home. Let it rest on a proper hanger and air it out. You will find more practical tips here: How to store a suit so it does not lose its shape.