When repairing a split fingernail with a tea bag, make sure the tea bag is made of paper instead of cloth. Otherwise, it will not work. Cut a rectangle out of the teabag, long enough to cover the nail halfway.
Apply a base coat to your nail. When it is mostly dry but still tacky, press the rectangular piece of teabag onto it, ensuring it covers the split. Smooth the paper down to keep bubbles and bumps out. The teabag helps strengthen the broken section of the nail. Once you successfully bond the paper to the nail, add another layer of base coat. File away excess paper and paint the nails any color.