This paper presents low-complexity "myopic sensing-transmission policies" (MPs) for distributed sensing and estimation in a wireless sensor network. The MPs optimize a trade-off between performance and cost for each sensor node. For a coordinated MP scheme, the policy is computed in closed form, while an iterative algorithm is used for a decentralized scheme to reach a local optimum. The MPs dictate that only the best sensor nodes activate when estimation quality is poor, otherwise all nodes remain idle to preserve energy. Thresholds for activation are derived in closed form and do not depend on the number of channels used. A single channel is sufficient for energy-constrained networks. The MPs provide near-optimal performance to the optimal policy with much lower