Need help. I’m a new dev trying to present my work to clients in a better way

As the title says, I'm very new to developing WordPress sites. I struggle with quoting prices for different custom projects. I try to do my best for each client by offering them more than what they are expecting but I want to look presentable and professional.

What are your tips and tricks about it?

I also want to know if it's better to give different quotes to all clients or make packages. What's best for long term?