Never, I tend to downplay my CV, because it is hard to get a job after redundancy when you�re Qualifications and Experience is so much better than the interviewers.
However, rather than lie, why don't you think about positions you have had and responsibility been given and describe them in a different way as advised by a previous poster.
E.g. till assistant could be 'responsible for receiving large amounts of cash and efficient reconciliation of days takings'
If you have a lack of Academic Qualification, what about clubs you have joined, after school activities, or interests. Use these in a good light.
Put your thinking cap on when composing a CV but keep it short. Readers have a lot of CV's to read, don�t bore them.