They say you teach people how to treat you.
But discovering how your customer is used to being treated can help you learn how to treat them.

If you’re working with customer who deals with angry customers in their own business, they may feel it’s ok or even necessary to show anger to get results.
If you work with someone whose customers haggle with them, on price, they’ll likely haggle with you too.
If your customer has customers who treat them as as team member or even a member of the family, then your relationship may be more intimate and positive with them than your typical customer.

So when you’re forming up your proposals, consider your customer’s customer.
Do they work on long term projects or small one-time purchases with tight margins?
Are their working relationships joyful or antagonistic?
Do they communicate with their customers via text? In person?
The list goes on – take a look at where attitudes and behaviors start. Valuable clues lie there.

Then model your project in a way that works for them. Bite-sized tasks may feel more natural for them than thinking about a full scale project. They may prefer to leave everything up to you or they may need a lot of communication to be confident that things are being done right. A positive atmosphere may be critical for them, or they may feel that the energy of friction is what gets the job done right.
It’s critical to have your own processes nailed down and not be pulled in all directions when you’re in the sales process, but considering how your customer sees the world may help you write a proposal that fits just right.