The more comprehensive the instructions, the more accurate the markup. Even though this statement sounds intuitive, instructions are often overlooked by requesters.
Good instructions give the performer a general idea of the project, explain how to work with new information correctly, and then serve as an up-to-date reference. The clarity and completeness of the instructions will determine the quality of the responses you receive and the project rating. Remember that someone seeing your project for the first time might not understand the concept and all the details, even though the task might seem crystal clear to you.
Instructions should be thorough and provide examples for every possible case. For instance, if there are several classes in your task, you need to formulate clear criteria for each class, as well as examples (preferably several) for each of them. Try to make your instructions understandable for non-experts and explain all the features of the task. You can also include information about training and payment schemes if appropriate.
Running your project in the sandbox
also involves testing the instructions, so do not hesitate to ask people (especially those who are not involved in the project) to read the instructions and comment on obscure parts.