The landscape orientation of smartphone offers a better aspect ratio and extensive view for watching media and photography. However, it presents challenges of occlusion, reachability, and frequent re-gripping in one-handed interactions. To address these issues we took the opportunity of deformation gestures to interact with future flexible smartphones. A preliminary survey was conducted to understand one-handed landscape mode usage patterns. Then, the 1st study was conducted to identify 3 most preferred one-handed landscape mode grips. In the 2nd study, we gathered unique user-defined deformation gestures to identify the set of most natural and intuitive gestures corresponding to each grip. We also found 3 gestures that can be performed in more than one grip. Finally, we discuss the influence of the grips on performing gestures. © 2019 Copyright is held by the owner/author(s).