There’s no secret to success.
Hard work, professionalism, quality work can bring success.
Meanwhile you can try to promote your gig everywhere specially in social media or you can promote gig based on your targeted customers.
You can active on your client’s timezone so that you can communicate them on time.
Be patience and keep working on your goal.
Beside this, I believe Luck is another important thing which can bring success.
Because some of user doing a lot of things and got few order but on the other hand, some of freelancer doing nothing to promote their gig but still getting order, maybe because of Fiver’s automated systems.