Can anyone help me with a Warehouse Operative cover letter?

Hello, I keep applying to jobs but I never get reply's and I'm guessing this is because I am really bad at wording cover letters and don't know what to write, Its for a Warehouse Operator, I already have 1.5 years of experience in this field including heavy lifting, loading and unloading vans dealing with deliveries and general upkeep of the warehouse. Any help would be a major help, Thanks alot!