These are some of the top skills ,that i think best on Fiverr.

Proofreading and Editing

Design Book Covers

Logo Designing

Virtual Assistant

Ad Campaigns

Creating Video Greetings or Intros

Digital Marketing

Article Writing

YouTube thumbnail editing

Graphic designer

Web designer

Even you have best Fiverr skills , it's very hard to get client's on Fiverr, due to an huge amount of competition.

In order to get client's your have to try different website rather than searching in huge competitive websites ..