It really depends on the type of aircraft. If the aircraft is equipped with a steering tiller then except when possibly manoevering off stand (if not getting pushed back) or other similar tight spots, when a combination of differential braking and opposite engine may also be used, all steering is soley via the tiller.
On a typical light twin not fitted with tiller steering, then a combination of rudder (linked to the nose wheel ), differential power and differential brake may be used.
On very old twins, usually taildraggers with cable operated brakes and no direct steering to the tailwheel, then a lot of differential power may be necessary at times, especially if the cables have stretched out of adjustment and the brakes are less than ideal. Whilst taxiing such an aircraft in a strongish X-wind a fair bit of differential power may be even be necessary to taxi in straight line.