If you wish to maintain a consistent style to all the documents you create, it would be to use a

I believe that the best answer to the question: If you wish to maintain a consistent style to all the documents you create, it would be helpful to use a:__, would be: a template.

Explanation:

The reason for this being the best answer is that templates are like standardized guidelines, or frameworks that literally allow anyone to continue the work of another, or their own, even if the information may be different. Templates are preset, pre-established frameworks, and they will ensure that throughout your work you stay consistent in style and form. It will also allow someone else to evidence that style and follow it, if they have to continue something you were doing.

to plan an idea out before

c it has to be i googled it