Having been on both ends of the hiring process (in tech):

1. You don't have to be 100% qualified. Just show me that the skills you have are transferrable.

2. Tailor your CV & cover letter to the vacancy and company. List at least one work/life/volunteering experience (preferably a project with end results) that is linked to each of the requirements.

3. Keep it short and to the point. A quick glance and relevant keywords should jump out and pique my interest.

4. If you go "but..." to any of the 3 points above, you're probably wasting everyone's time.