It depends on what the sentence would look like if you phrased it as a statement rather than a question: in particular, what is the main verb, and whether there is a modal / auxiliary verb (must, will).

For sentences with a modal, you simply move the modal to the front:

You will need a car
Will you need a car?

If the is no modal and the main verb is be, you move the main verb to the front:

This is your hat
Is this your hat?

If there is no modal and the main verb is not be, you add do, and convert the main verb to a bare infinitive:

Your company works on PHP?
Does your company work on PHP?

have is complicated, because it can be either modal or not.

You have seen him. -modal
Have you seen him?

You have got a car - modal
Have you got a car?

You have a car - non-modal
Do you have a car?

It depends on what the sentence would look like if you phrased it as a statement rather than a question: in particular, what is the main verb, and whether there is a modal / auxiliary verb (must, will).

For sentences with a modal, you simply move the modal to the front:

You will need a car
Will you need a car?

If there is no modal and the main verb is be, you move the main verb to the front:

This is your hat
Is this your hat?

If there is no modal and the main verb is not be, you add do, and convert the main verb to a bare infinitive:

Your company works on PHP?
Does your company work on PHP?

have is complicated, because it can be either modal or not.

You have seen him. -modal
Have you seen him?

You have got a car - modal
Have you got a car?

You have a car - non-modal
Do you have a car?