Mishpatim Bulletin in PDF format

One should pause slightly between answering ‘amein‘ to the chazzan’s ‘hamachazir shechinosso l’tziyon‘ and starting ‘modim deRabonon‘; they are unconnected, and to say them together as one sentence is incorrect.

It is preferable to daven facing a wall, without any intervening object. (The following are NOT considered intervening objects: permanent furniture; an object used during davening to hold the siddur; anything less than 10 tefachim high or wide; another person [mai’ikar hadin]. )

Besides the obvious reason of possibly getting distracted, the Levush says that the reason is that we are emulating the rules in the Beis Mikdash, where such interventions were forbidden in various aspects of the avodah .