I'm not sure if one-handed technique makes you a better pilot that two-handed or vice-versa. However, I was taught to use only the left hand despite having a throttle on the left as well as in the centre (R2160). In any case, it was a column, not a yoke, so I could only use one hand. This got me into the habit of keeping one hand more-or-less permanently on the throttle when not using it for anything else.
This was a bit of an arm-ache at first, and I'm not sure that under normal ops it is necessary, but in the event of a collision avoidance manouvre I'd be happier not having to spend an extra half a second reaching for the throttle! Other than that, I'd say it comes down to just personal preference, but I would say that there's something wrong if you need more than one hand's worth of pressure to move the controls.
AD