Select examples of your strongest points at earlier positions. These examples should highlight the skills required by the position that you are applying for.
You can tell that you are (be prepared to give details)
e.g., experienced, competent, honest, teachable, patient
have the following skills:
e.g., IT, Internet research, management/leadership, material design, Moodle, Hot Potatoes, etc.
Get a few more ideas here...
Also, you will find a few useful tips here...