Touchless gestural controls are becoming an important natural input technique for interaction with emerging virtual environments but design parameters that improve task performance while at the same time reduce user fatigue require investigation. This experiment aims to understand how control-display (CD) parameters such as gain and mapping as well as the use of armrests affect gesture accuracy in specific movement directions. Twelve participants completed temporally constrained two-dimensional steering tasks using free-hand fingertip gestures in several conditions. Use of an armrest, increased CD gain, and horizontal mapping significantly reduced success rate. The results show that optimal transfer functions for gestures will depend on the movement direction as well as arm support features.