Dental Health professionals advices you wash your mouth twice a day(after breakfast and at night after dinner).
Avoid using hard brushes so you won't damage your oral tissues.
Avoid eating sugary stuffs, reason been that oral microscopic organisms works on the sugars on the surface of the tooth and releases a destructive acid on the tooth which leads to tooth decay and this also leads to halitosis.
Rinse your mouth after taking whatever.
Chewing gum isn't bad in itself, it becomes bad when you spit it out while it's sugar is still intact, so it's advisable you keep chewing gum even after the sugary content has been washed away so it help increase the secretion of saliva that washes away the sugary content on the tooth surfaces.
I hope this helps. Thanks for reading.