These tips on mediation advocacy are aimed at plaintiffs' lawyers but are widely transferable.
Examples: "Don’t reveal your bottom figure too soon, even to the mediator."
"Be patient. Most large cases do not settle quickly. It may take more than one session."
Your client's "anger will create an impediment to settlement. In addition, your client may not understand why her lawyer is candidly admitting weaknesses."
These tips for lawyers representing clients in mediation are by Roger Booth via Donna Cole.