Accessible Form Fields

I understand the basics of form fields and how they require labels, instructions and groupings in order to be accessible. This is simple enough for a fillable form. What I'm looking for is a good example for form fields when they are in assignments.

How would you label a text input field, a drop down selection menu, or even group a set of radio buttons and associate it to a question that could be a paragraph long or even more complex? I don't believe it would be ideal to make the question itself a label for the form field especially in this scenario.

What would be the best practice and what should one be looking for when checking this type of form fields for accessibility?

This sure if this question is going to the same place. Apologies if it is.