I use a gantry crane like that here in my shop, and I don't have any problems with the load swinging when I lift, except when I do not have the crane centered over the object's center of gravity.
When you lift something from a position not over it's center of gravity (or even worse, not even directly over the object at all), as soon as it's free of the friction force of the ground, it immediately seeks to center itself under the crane. The result, as we all know, is positive overshoot, followed by negative overshoot, followed by positive, and so on... (swinging).
So, just get your crane centered properly before you lift.
EDIT:
if I am lifting something that I cannot identify it's COG; for example your 1m cube, which may be a box of unknown, unevenly loaded contents, I lift from the visual center, just little bit of upward motion but not all the way off the ground. When the box just barely begins to lift up, it will start to slide a bit on the ground (one corner will drag). This partially-engaged friction on the ground greatly dampens the oscillations compared to had I just quickly lifted it up off the ground. This brief period need only last a second or two, then you can start lifting up. Once you've got the technique down, it does not add any appreciable time to your routine.
When you lift something from a position not over it's center of gravity (or even worse, not even directly over the object at all), as soon as it's free of the friction force of the ground, it immediately seeks to center itself under the crane. The result, as we all know, is positive overshoot, followed by negative overshoot, followed by positive, and so on... (swinging).
So, just get your crane centered properly before you lift.
EDIT:
if I am lifting something that I cannot identify it's COG; for example your 1m cube, which may be a box of unknown, unevenly loaded contents, I lift from the visual center, just little bit of upward motion but not all the way off the ground. When the box just barely begins to lift up, it will start to slide a bit on the ground (one corner will drag). This partially-engaged friction on the ground greatly dampens the oscillations compared to had I just quickly lifted it up off the ground. This brief period need only last a second or two, then you can start lifting up. Once you've got the technique down, it does not add any appreciable time to your routine.