If you don't dress to impress I strongly recommend that you start doing it now. Nowadays you will be taken seriously if you dress the part. If you dress up casually for a job interview, you are automatically excluding yourself from the short list. This is true and I am not here to give you bull.
I know sometimes it is stressful to put on long sleeve shirts on a sunny day or those tight uncomfortable shoes. But this is what you have to do to maintain your position and to keep growing in your career.
So start dress to impress and cut the bat bad habit of don't giving a crap. Sometimes you look like a clown while tucked in but it pays off at the end, Big time! And suddenly you are not the clown but a successful person with lots of opportunities and cash.