One of the major drawbacks of a touchscreen gaming device is the lack of tactile button feedback. Some games have attempted to fix this by using relative button positioning, which changes the center of the virtual D-pad depending on where your finger is. This helps, but isn’t nearly as dependable as physical buttons.
A Japanese company now offers a simple, yet innovative solution: Transparant screen “stickies” with small bumps, so you know where your fingers are (much like the bumps on the F and J keys on a keyboard). They may not work well for all games, due to the variety of keypad layouts, but they should function fine for most.
A 2-pack can be purchased from shady over-sea site for less than $8, which isn’t terribly expensive, but hopefully cheaper alternatives are created by vendors state-side.