The Tenth and Eleventh Doctor concurred that the key to perfect negotiation was "not knowing what side you're on". (TV: The Day of the Doctor)
During the 2323 Dalek invasion of Earth, the World Government sent a communication to the Golden City Zone, offering negotiations for total surrender. The Golden Emperor rejected this, offering only subjugation. (COMIC: Liberation of the Daleks [+]Alan Barnes, DWM Comics (Panini Comics, 2022-2023).)
During the Last Great Time War, the Battle TARDIS sent to collect Susan Foreman was ambushed by Daleks. When the Daleks began using the ship to steal power from the Eye of Harmony, the Time Lords attempted to remotely take control of the TARDIS to no avail. At Susan's advice, the Time Lords sought out the telepathic talents of the Sensorites to take control of the TARDIS via its telepathic circuits. Susan was sent to lead the negotiations, discovering a Dalek-Sensorite parasite within the Interior, increasing the Sensorties' paranoia. When the Sensorites learnt of it, they immediately cancelled the negotiations, now fully convinced of the Dalek threat and readily lent their aid. (AUDIO: Sphere of Influence [+]Eddie Robson, Susan's War (Big Finish Productions, 2020).)