While in general we try to keep to a minimum the times we cross back and forth from one side of the Holy Altar to the other, so as not to distract the faithful by constant movement, there are of course legitimate times when servers and clerics do need to move from one side to the other. On these occasions, it is fitting that we reverence the High Place as we pass it by, which is done in the following manner: As we walk behind the Holy Table, we make the sign of the Cross over ourself as we pass by the Holy Place, slightly inclining our head as we keep walking. We do not stop, nor slow ourselves, at the High Place to make the sign of the Cross, nor do we make a protracted bow; nor yet do we bow to the celebrant cleric or Bishop (this is a misappropriation of the formally-appointed times when it is called for in the rubrics for bows to be made to the High Place, and from there to the celebrant). We simply make a pious sign of the Cross over ourselves as we walk, and continue to our destination.
If when we are crossing to the other side of the Altar, we are carrying something that requires both hands, we simply walk piously across without making the sign of the Cross.