A first suggestion would be to wear your blazer with a cardigan having the neck shaped in V. This way, you will look stylish and also smart and you will definitely in the right spot in terms of fashion and fashion trends. Wearing your blazer like this will give the impression that your T-shirt is your second layer of skin and therefore you will not have any part of your chest exposed. You will also feel comfortable and you will have a classic touch which is always something that catches the eye.
Secondly, you can wear it over a plaid shirt, this way being very modern and inspired from the point of view of fashion standards. You can choose a checked shirt in white and blue for instance and this will certainly match your new navy blazer and even your new black one.
If you wear your blazer with a chunky pullover, you will also let people know that you know a few things about fashion, because this seems to be a very popular trend these days. Not only will you look like a gentleman, but you will also look quite formally dressed, which of course,