Improve your gigs.
Tial and error. Post a few gigs with the same service. Make them different. Test different images, descriptions and keywords.
Edit, improve gigs that don't get traffic or don't convert.
Log in to fiverr every day. This might not be proven to work, but I think fiverr pays attention if you are active or not.
See what are the most popular gigs and replicate it in your own way. Check their keywords for example.
If you can, offer a better service.