When pushing, instead of cranking hard on the steering (whatever type it is) to try to turn, which is hard on the machine, lower the corner of the blade in the direction you want to turn.
For example, if bulk pushing, and you need to adjust your alignment a little to the right, lower the right side of the blade, which will cause that corner bit to dig in a little deeper. That will steer the machine to the right.
To turn sharper, if you're cutting out of a big windrow (between two slots, around a boulder) you can lower one side of the blade and raise the other to line out straight in the direction you want to go. This will lower the weight on one side, and increase the resistance on the other to turn the machine sharper.