The methods section will be expanded and include extensive information on why you chose the research method you propose and why you rejected others. A proposal, therefore, might have the following outline:
pages 1 – 3, presentation of the research question and motivating context (why we should care) pages 4- 5, literature review page 6, proposed research design pages 7-10, discuss why you selected your specific method (for example, ethnography).
page 11, conclusion What about the research question makes your chosen method best suited to answer it? Why did you not choose quantitative methods (if you did not choose mixed methods)?
If you chose mixed methods, what do you expect each element (the quantitative and the qualitative) of your methodology to address?
Suppose you chose a single qualitative method (again, such as ethnography). What about that method makes it better suited to answering your question than other qualitative methods (such as content analysis or interviews)? In short, the core of your proposal is a defense of your methodological choices.