When deciding on which techniques to apply it is vital to do so in terms of the appropriateness of the technique to the research question and the feasibility of the technique in the context.
You must consider practical issues such as the time you have to conduct the fieldwork, availability of the people you have sampled, the nature of the environment and the feelings of those you have sampled.
Always be aware that you must retain a rapport with the community; you are not making a one-off visit then leaving with your rapidly harvested data.
You will be spending some time in this environment so it is essential that you remain sensitive to the demands you are placing on your sample group.