In the case of a previously-owned LP: I remove the LP and the inner paper sleeve from the slipcase. Then I wrap the LP and the slipcase in two sheets of tissue paper. I place the wrapped LP / slipcase and a piece of firm cardboard inside a special box that is manufactured specifically for shipping records. I tape all the edges securely. For larger shipments, I use bubble wrap. For new LPs, I wrap in tissue paper, then ship in cardboard mailer, as discussed above.