PROSPECTION as Junior Sales Broker: Advice needed

Hi folks

Intro
Coming from a french business school I recently finished my 6 months internship in France and I am moving to London to work within a prime brokerage firm (Valbury Capital). This firm gave me some months of Trial, and if I am not profitable after those, they end my contract, fair enough. I decided to take the challenge.

Nevertheless, I did not have time to prospect for new clients during my internship and, for my next job I will have to prospect institutional clients to build my entire portfolio, which make sense.

Issue
Working on Equities, do you have some advice to prospect institutional clients? As my company is a gateway to Asian equities I will build my speech around that argument but, I term of soft skills, way to approach client or anything else, I really need some tips and clues.
Could you share with me your experience if you already worked in a brokerage firm building a portfolio of client or prospecting new clients?

Thanks a lot in advance!