This document analyses which methods are currently being used in Tropenbos research dealing with non-timber forest products (NTFPs). First, a distinction is made between several key conditions for successful and sustainable commercial NTFP extraction. Amongst these are: the availability of natural resources; sustainable harvest levels; the compatibility of extractive activities with other economic activities; access to markets; and participatory planning. The methodologies which are being applied to provide insight into one or more of these key conditions are described, giving attention to their respective advantages and disadvantages. The overview shows that methodological choices depend on each study's specific objectives and context. The integrated results of these studies can make clear under which conditions commercial extraction can serve as a strategy for conservation and wise forest use.