First things first... send the Ferengi a subspace transmission from the "Prince of the Klingon Homeworld" stating that my father was recently kidnapped, and in order to claim his billions of bars of gold-pressed latinum, I had to have a small amount of their money sent in order to cover the legal fees and what-not. Once they sent me all their account info, I'd rob them blind, and then enslave them to their own lost riches. After that, I'd buy every Klingon and Cardassian a drink and a holo-suite program... ya know, so they "owe" me one (you can never have enough favors to cash in!). After that I'd probably buy Risa, and slowly black mail every Federation official that came through there (since they all apparently eventually do). Oh, I'd also buy exclusive trademark rights to the "IDIC" symbol, and request a minor stipend each time it was displayed on Vulcan. Also, I'd develop and f'in EMP that could disable the Borg... don't want them getting in my hair. Finally, I'd develop a new, cheap method of manufacturing Romulan ale, and slowly corner that market, to the point where all domestic distilleries can't compete with the intergalactic conglomerate that is RomBev (lol InBev), and then slowly introduce an addictive carcinogen into their beverage of choice, and through addiction take complete control of that civilization...
So to recap, I'd pretty much just go Godfather on them... and they can all kiss the ring ;-)