Address the issue
If you lack experience, don't try to brush over the fact. A cover letter is the perfect place to address any gaps in your CV, so use the opportunity to address any concerns the employer might have. Then...
Focus on what you DO have
Experience is important, but so is your attitude to work, your personality, your understanding of the company and its activity, motivation, resilience, ideas for the future - the list is endless, so don't get too hung up on any one thing.
Find experience you didn't know you had
Before you decide you don't have the experience, make absolutely sure this is true. Think back over your past jobs and try to draw links between the experience you need and the experience you have. Remember: it needn't be exactly the same; the key word to keep in mind is relevant. If you've organised a meeting or answered the phones, that's admin experience. If you've set up a Facebook page or created a flier, that's marketing. Think outside the box!
Create some experience
Do some voluntary work, work experience, or an internship.