Don't make unpleasant remarks about people.
Dont' tell the borrower what a terrible slob your last client was, or how mean the signing company was who you were employed by yesterday. That will leave a terrible impression. British social norms win the game in the signing business. That means keeping a stiff upper lip, a well inked seal, and sticking to talking about the weather. You can read articles about the weather so you can be conversant about the rain in Spain, the monsoon season in Kerela, and how the word Typhoon evolved from the Cantonese word Dai-Feng ( big wind ) and is Feng-Dai in Taiwanese ( the words are reversed ).