The Sha’ar Ru’ah Ha’kodesh (Rav Haim Vital, 1543-1620) warns that one should never interlock his fingers, as doing so can bring the divine attribute of judgment upon a person. This applies all year round, but is especially important during the period of the Aseret Yemeh Teshuba, when we are already in a state of judgment. One should alert his family members, as well, to avoid interlocking their fingers so they can avoid the divine attribute of judgment.
The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) mentions that one should always ensure to keep his hands in front of him, rather than in back of him, as the forces of strict judgment are located in the back. Once again, although this applies all year round, it is especially important to be mindful of this during the Aseret Yemeh Teshuba. The Ben Ish Hai further noted that the Sadikim always make a point of giving precedence and superiority to the right, which signifies the attribute of kindness, as opposed to the left, which represents the attribute of judgment. Thus, when they bring their hands together they ensure to place the right over the left, and when they clap they make sure the right is on top. Likewise, when dressing they ensure to first put on the right garment before the left garment, so that the attribute of kindness will always overpower the attribute of judgment.