Deep Neck Flexor Exercises Need Suggestions About What Undergarment I Should Wear Under My New Deep V-Neck Dress?

Need suggestions about what undergarment I should wear under my new deep V-Neck dress? - deep neck flexor exercises

I bought a new dress to wear, and I ask myself what I wear a bra should include, as it is deep and V shows a normal bra. Proposals on the different types of fasteners and other accessories (ribbon / stick ons)? If you do this, please tell me how easy it is and how well it works.

Thank you.