We explore how the choices available to individuals planning multi-task work can facilitate the incubation of ideas and enhance creative performance. Using opportunistic assimilation theory, we hypothesize that two considerations can determine the effectiveness of incubation and creative performance. First, we argue that having the discretion to switch tasks when needed, as well as the timing of this discretionary switch between tasks (i.e., earlier versus later in the work process on the main task) is important. Second, the scope of the intervening task (i.e., in the same knowledge domain as the main task versus in a different domain) can lead to more effective incubation and creativity. Results of a laboratory study indicate that participants who made a discretionary switch to an intervening task later in their work process on the main task benefited significantly more in terms of creative performance than those who chose to switch earlier in their work process or chose not to switch tasks. Additionally, participants who worked on an in-domain intervening task exhibited significantly higher creativity on the main task than those who worked on an out-of-domain intervening task. Furthermore, focus of attention on the main task partially mediated these results.