There are several key analytic strategies.
Coding is a process for both categorizing qualitative data and for describing the implications and details of these categories. Initially one does open coding, considering the data in minute detail while developing some initial categories. Later, one moves to more selective coding where one systematically codes with respect to a core concept.
Memoing is a process for recording the thoughts and ideas of the researcher as they evolve throughout the study. It can be thought of as extensive marginal notes and comments. Again, early in the process these memos tend to be very open while later on they tend to increasingly focus in on the core concept.
Integrative Diagrams and Sessions are used to pull all of the detail together, to help make sense of the data with respect to the emerging theory. The diagrams can be any form of graphic that is useful. They could be concept maps or directed graphs or even simple cartoons that can act as summarizing devices. This integrative work is best done in group sessions where different members of the research team are able to interact and share ideas to increase insight.
Eventually one approaches conceptually dense theory as new observation leads to new linkages which lead to revisions in the theory and more data collection. The core concept or category is identified and fleshed out in detail.