As the former assistant at the [Company Name], I learned how to handle a wide variety of tasks and understood the importance of always providing service of the uttermost (supreme) quality. In addition, self-sufficiency and responsibility was core and prioritised to ensure my success as assistant.
My duties as assistant (to [Name of Person]) included meetings with state officials, leading projects, writing press releases and travel planning.
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Baserat på din egen struktur eftersom jag inte vet exakt vad du har jag gjort blir det lite svårt att skriva om det. Tror det är vad du menade med det olika XXXX:en.
Man skulle kunna byta ut "...I learned how to handle..." till något i stil med "I developed skills and adapted to my environment to be able to conquer the most difficult of tasks" eller något annat lite mer "cheesy" som dom värkar gilla i engelsktalande länder
Edit: Råkade skriva utter most istället för uttermost. My bad. Sen kanske man kan skippa supreme eftersom det blir dubbelmening över det hela ^^