This is an excellent article that explains the characteristics of twice-exceptional students and shares some profiles of students that fall into the category. It also gives you some strategies to try in your classes to help meet the needs of these students.
NEA has provided this document, which will help you understand the twice-exceptional student. It includes ideas for the classroom teacher to use in teaching these students. There is also an excellent resource list for further information.
These lists were developed by teachers taking part in a course. While you might be overwhelmed with the number of ideas, pick one list to start with. You will certainly find ideas to try with your students.