I have hired multiple times from Fiverr, Freelancer and Guru.

NOTHING CAN GUARANTEE A GOOD RESOURCE ! You have to vett couple resources and find the right person who
- Can understand your thought process
- Can communicate with you easily
- Have done similar work before
- Have some reviews against him..

What I generally do
- I give a small gig to see how much we good is the communication and understanding
- Ask questions to the reviewers (both positive an negative) to share some more insight into the engagement
- Create milestones and check rough cuts frequently in the process of development
- Creative writing and design works is very different. You need a person whom you can connect with..