First off, with the tail draggers, it's a good idea to touch down at just above stall speed. You want to get your tail wheel on the ground quickly to add directional stability.
Secondly, in AH to lock the tail wheel you merely pull back on the stick about 15 degrees. Which is another reason to come in slow...you want to lock the tail wheel, but not create enough lift to leave the runway. Usually if I used flaps on approach, I am retracting them as I touch down, so I can pull the tail down for ground contact, and lock the wheel.
Also take it easy on the toe brakes. Some models are more nose heavy than other, and will easily prop strike if you are hard on the brakes. Typically in the few seconds it takes to get the tail down and locked, I am lightly adjusting on the right and left brakes to keep it straight.
And lastly, go into options>controls>map controlers, and make sure the 2 sliders are set to "analog inputs brake left" and "analog inputs brake right", and that the numbers in parenthesis respond accordingly. You can also click on the Calibrate Axis button while having one of the slider axis highlighted, to adjust it if you are not happy with the calibration.
