The Ultimate truth
The #1 rule of selling on Fiverr is simple to Be awesome and deliver a great product. Every client you meet will want pure awesome-sauce every time, and if you’re not giving that, they’ll go somewhere else. There’s plenty of room for mediocre sellers on Fiverr, but if you want to stand out from the crowd, you need to be real, really good at what you do.
Generally speaking, though, this rule is dominant in any sales environment. Doesn’t matter if you’ve got a brick-and-mortar store, you’re working for somebody else, you’re selling via your own website, or you’re selling via Fiverr: quality products and services can speak for themselves and can overcome a lot of other shortfalls.
If you’re not really, really good at what you do, then you really, really need to get better. This doesn’t mean that you shouldn’t sell on Fiverr, but it does mean that you should be actively and consistently engaged in a process of self-improvement to raise the quality of your offerings.