Legal Method for Adjusting Pieces
USCF Rule 10A, p.21, Adjustment of Pieces.
"A player who is on the move and first expresses the intention to adjust (e.g. by saying j'adoube or I adjust) may adjust one or more pieces on their squares."
The distracting practice of adjusting pieces on your opponents time is a violation of the rules and may result in a time penalty. In addition, neither player has the right to "hover" his hand over the board, in effect, obscuring his opponents vision. Repeated violations may also result in a time penalty.                  TD