Use .form-control on <textarea> for multiline values such as notes, messages, summaries, and review context. Pair it with a visible label, choose a starting rows count that matches the expected amount of writing, and keep placeholder text as an example rather than a replacement for the label.
Place helper or error text directly below the textarea and connect it with aria-describedby. Use validation state on the native control, and keep constraints such as required, disabled, readonly, maxlength, or minimum guidance close to the field.
Keep Textarea for short to medium plain text. If users need rich formatting, attachments, comments, or long-form editing, move them to a larger editor surface rather than stretching a form textarea into a document editor.