Process modifications can include adding (or substituting) higher-order thinking, open-endedness, group process, freedom of choice, proof and reasoning, pacing, and flexibility.
Think about a specific lesson that is coming up soon. Now, how can you adapt it to allow for some of these elements? Can you incorporate higher order thinking opportunities for some students? Is there a place where you can leave things open ended? Is it possible to have students working on this in a group? Are there elements of choice that can be exploited for the benefit of gifted students? What about allowing for acceleration for some students? These are good principles to keep in mind as you consider the effect of the lesson plan on gifted students.