Formal:
* Bom dia, meu amor. (Good morning, my love.) - This is the most common and polite way to say it.
Informal:
* Bom dia, meu bem. (Good morning, my dear.) - This is a more affectionate way to say it.
* Bom dia, amor. (Good morning, love.) - This is very informal and is typically used between couples.
More romantic:
* Bom dia, meu/minha (your name) . (Good morning, (your name).) - This is a very personal and intimate way to say it.
* Bom dia, meu/minha vida. (Good morning, my life.) - This is a very affectionate and romantic way to say it.
You can also use different variations depending on the context and the person you are talking to.
For example:
* Bom dia, meu anjo. (Good morning, my angel.)
* Bom dia, meu/minha sol. (Good morning, my sunshine.)
* Bom dia, meu/minha tudo. (Good morning, my everything.)
Remember to choose the option that best suits your relationship and the context of your conversation.