Recently, pen tilting has been explored in pen-based user interfaces and has shown potential to improve user interaction in various tasks (e.g., menu selection, modeless object manipulation). However, some basic questions concerning pen tilting behaviors, such as the ideal range, azimuth size, and direction of pen tilting, have not been thoroughly investigated. In this paper, we report our empirical studies on user performances in basic pen tilting tasks. First, we conducted a baseline study, which helps us to determine tilting directions, tilting ranges, and the thresholds that separate incidental pen tilting actions from intentional actions used for interaction. Based on the results from the baseline study, we designed an experiment to investigate user performances in goal tilting in different tilting ranges, azimuth sizes, and directions. Drawing on the results of our data analyses on task completion time, error rate, and pen tip movements, we discussed values of tilting parameters like titling range, minimal azimuth size, and tilting direction.