Be as descriptive as possible. Provide samples and explain what you expect from anyone who accepts this trade. The more details you add, the easier it will be for coders to live up to your expectations. Users will use this description to view and make offers on your trade.
Do not use images already in use by other services
Image must be descriptive and relevant to your work
Real work sample images sell many times more then others
Never use other seller's images
Acceptable formats: jpeg, jpg, gif and png