Common reasons for the refusal of child visa applications to the UK include insufficient financial evidence, incomplete or incorrect documentation, lack of parental consent, and failure to meet specific visa requirements (like an unconditional offer from a school for a Child Student Visa). To avoid these issues, applicants should ensure they provide comprehensive and accurate financial proof, submit all required documents, include clear parental consent, and carefully follow the visa guidelines. Double-checking the application for completeness and accuracy before submission can also help prevent refusals.