A software architecture is carefully designed to satisfy the quality concerns of its stakeholders, and as such, represents a systematic and intricately balanced set of design decisions which deliver required qualities such as performance, reliability, and safety. In practice, architectural degradation tends to occur over the lifetime of the software system, as developers make ongoing and incremental maintenance changes to the system without knowledge of its underlying design decisions. Fortunately, this problem can be alleviated by establishing traceability between concrete elements in the architecture and their associated design decisions, and then using these traceability links to keep developers informed of relevant architectural tactics, styles, and design patterns throughout the development process. This paper focuses on the task of creating and using such traceability links. We present six trace creation patterns describing techniques and supporting structures for creating architecturally significant traceability links, and two usage patterns describing techniques for using the created links to help preserve qualities in the architectural design. The patterns described in this paper emerged from our experiences and observations of tracing architectural concerns in safety critical systems.