In inspiration and fixation experiments, example designs are often provided along with the instructions for how participants should treat them. However, research has not reached a consensus about the influence of such instructions, leading to difficulties in understanding how the examples and the instructions each affect idea generation. We conducted an experiment in which 303 participants designed for the same design problem, while given different examples and instructions, which ranged from strongly encouraging copying the examples to strongly discouraging copying. Exposure to the examples affected the number and type of ideas generated, whereas exposure to the instructions did not. However, instructions did affect how participants incorporated features of the examples in their ideas. Encouraged groups incorporated many features of the examples, while also incorporating structural features more than conceptual ones. Surprisingly, the incorporation of features in discouraged groups was not different from that of groups given no instructions or even no stimulus. This indicates that concrete features may be easier to recognize and reproduce than abstract ones, and that encouraging instructions are more effective than discouraging ones, despite how strict or lenient those instructions are. The manipulation of different features also allowed us to observe how similar approaches to solving a design problem can compete for attention and how the calculation of feature repetition can be misleading depending on how common or obvious the features might be. These findings have implications for the interpretation of results from fixation studies, and for the development of design tools that present stimuli to assist idea generation.