While researchers have looked at many aspects of argumentation, an area often neglected is that of argumentation strategies. That is, given multiple possible arguments that an agent can put forth, which should be selected in what circumstances. In this paper, we propose two related heuristics that allow an agent to select what utterances to make. The first involves minimising the amount of information revealed in the course of a dialogue. The second heuristic assigns a utility cost to revealing information, as well as a utility to winning, drawing and losing an argument. An agent participating in a dialogue then attempts to maximise its utility. We present a formal argumentation framework in which these heuristics may operate, and show how they function within the framework. Finally, we discuss extensions to the heuristics, and their relevance to argumentation theory in general.