Custom writing is not a specific type of paper. It covers all types of writing works including essay, research paper, article, content and many other. You should use proper grammar, style and format applicable for each type of custom writing. Review the written material several times to eliminate all the mistakes and run-on or vague sentences. Check on material for each type of custom writing to make sure that its structure is followed. Written material should be easy to ready, and interesting otherwise the readers would get bored and not finish reading. Better to take time searching for interesting facts, sources and topics.