The field of aerial robotics has advanced rapidly, but the design knowledge has not yet been codified into reusable design guidelines. Design guidelines have been developed for many mechanical design areas to advance the field itself and help novice designers benefit from past expert knowledge more easily. We used an inductive approach and collected 90 aerial robot examples by reviewing recent work in aerial robotics and studying the key motivations, features, functionalities, and potential design contradictions. Then, design guidelines are derived by identifying patterns and grouping them by the problem they solve and the innovation made to solve it iteratively. From this, we find 35 unique design examples that can be grouped into either 14 design guidelines for more sensing, battery, mission, or actuation efficiency; or to improve the desired functionality in an aerial robot such as reducing complexity or improving how the robot can interact with objects or its environment. The derived guidelines are validated for thematic saturation using convergence analysis and its utility through a qualitative design study involving novices and experienced designers working on two design problems. The design guidelines presented in this research can support the design of future innovative aerial robots.