Tips from the experts:

Give enough notice. You need time to build consensus around a new leader and to orient that leader to the post, consultants say. Robert Dell, Latham’s outgoing managing partner, gave his firm 13 months’ notice that he would be stepping down. Contrast that with Reed Smith. Last October, Gregory Jordan, the firm’s 13-year global managing partner, announced that he was leaving the next month to become general counsel at a client company (PNC Financial Services Group).