I floss after every meal and almost every snack.I brush multiple times a day.I use mouthwash.I rinse my mouth out with water a lot too.I don't smoke.I see the dentist regularly.Those basic things help considerably with bad breathe.
Heart health, too.
British people have the worst breath. Next up are Asians and blacks.
Coffee doesn't help. I had a primary school headmaster who had awful coffee breath all day long. I can still smell it 20 years later.