Flexible interaction technology became a one of key technology in nowadays. On the other hand, there are relatively little works has been done to understand how it should be designed especially for feedback of it. In this study, we investigate the guidelines for design feedback to flexible interaction systems through based on user’s expectation on them. We conducted user participated design workshop to collect user’s perspectives about feedback when they use flexible interactions. We gave 8 sets of actions which are generally used in flexible interaction and let 6 participants to generated ideas about visual, sound, and haptic feedback of them. From discussion session in the design workshop, we found out key factors about feedbacks. As a result of design workshop, we build guidelines of designing feedbacks for flexible interactions. This result will lead system designers to build flexible interaction to create flexible interaction which can improve the user experience.