Cognitive strategies are the specific methods that people use to solve problems and/or exploit opportunities, including all sorts of reasoning, planning, arithmetic, etc.
Importantly, a cognitive strategy need not be all "in the head", but will almost always interact with various aspects of what might be called the "execution context".
A specific cognitive strategy would be implemented via a set of ordered and overlapping logic.
Each logical aspect of a cognitive strategy is either taught or learned and needs to be remembered as situation foreknowledge.
They can be thought of as consciously written and remembered "programs" or as the "software" that guides future brain-neuron processing.