To wear a tube top with a bra, first select a strapless bra that fits snugly and provides adequate support. Position the bra on your body and fasten it securely. Slip the tube top over your head and adjust it to the desired level. Smooth out any fabric wrinkles or folds to ensure a clean and polished look. If you experience any slipping or discomfort, consider using a bra extender or attaching the tube top to your bra with safety pins for added support.