I started dressing better a few years ago.
The merino wool sweaters are a good start. I'd also look for slacks that fit well and comfortably. I have procured a few blazers that I got tailored. Pocket squares go a long way to jazzing up that look, too.
I also invested in some watches (Tissot, Hamilton), some decent shoes (nothing too crazy -- Allen Edmond or Thursday boots, that sort of thing). And, of all things, hats. Like proper felt fedoras. They're making a bit of a comeback. And they can make a fella look sharp.
Thin leather jacket -- black and brown. Look for them with lapels rather than racer or moto style.
When we go out now, we both make an effort. It's a little thing but it matters. Boosts confidence, projects class.