I understand most of the application forms are based on competencies now. They'll ask you for a certain number depending on which job you are applying for (there are a huge number of civilian jobs these days which require higher qualifications than that of a PC). You must think of things you've done throughout your life and break them into three parts. You detail what the problem was, explain how YOU solved it and how YOU went about solving it. For example: My friend was thirsty so I made a cup of tea by boiling the kettle and placing a teabag in a cup.
If you've solved a problem as part of a group and you state 'we did....' - they are not interested. It's about YOU only. Don't think that examples have to come from work experiences either, they can relate to things that have happened in your personal life and don't even have to be recent. Try to think of several examples for each competency because if you're lucky enough to get an interview, you'll be asked for more! You only have to score a certain number of points to get through paper sift - the pass mark is national and (unlike the private sector) you will not have your application excluded just because someone took a dislike to your handwriting! So make it good enough to get through but save your very best examples for interview - that's where the marking could vary depending on the interviewers. Good luck.