Use lack of information as a negotiating tactic. Discourage written communications. Don't anger the other side by arbitrarily moving slowly. Weaker , move the deal along without showing anxiety. Threats may be useful, but time them carefully.
Preparation is the best antidote to fear.
Assume the other side is anxious but not showing it. Be careful it is not ego, a great destroyer of what could have been good deals. What goes around comes around. The side with the higher level of decision-maker. The side paying greater attention.