I'll admit that I uh, haven't always had the greatest hygiene. I would wear dirty clothes if they looked clean, I would sleep in some days and skip my shower, I'd forget to put on deodorant or brush my teeth, ect. It was really just that I never got into the routine when I was younger, and I never really noticed how I smelled because I couldn't smell it. By the time I was aware of some of these problems, I was too stressed out about other things to care. Not to mention that I think I was slightly depressed but let's not get into that.
I've rapidly gotten much better about it recently. Scheduling really helps. I have a second alarm in case I sleep through my first one to guarantee I always have time for a shower in the morning. I have a dedicated laundry day every week that I never miss. I leave my deodorant stick where I can see it when I'm getting dressed every morning so I never forget to put it on.
On that note, and laundry is really important thing I never see anyone actually talk about. I got in the habit of showering and wearing deodorant, but it wasn't until I started doing laundry consistently that people stopped complaining.