Invest in your staff.

Hire, schedule, train, and communicate.

First - Hire staff to ensure adequate coverage of the sales floor. In most cases, you will now have a larger pool of candidates to choose from, and they will be more qualified than usual. Maximizing customer service may require only a marginal increase in staff. (As an alternative, schedule your existing staff more intensively.)
Second - Pay attention to scheduling. With increasing periodicity of purchasing careful scheduling will provide maximum floor coverage of existing staff. Make the most of what you already have. Your customers will be more loyal, and so will your staff. (Loyalty is function of security, not fear.)
Third - Allocate time to training existing staff. Make your remaining staff more effective with customers. Work on effectiveness, rather than efficiency. Instill a feeling of security. Emphasize opportunities.
Fourth - Communicate. Tell your staff the truth. (They probably know already.) Tell them what is happening, what will happen and what to expect. Be open and be positive. Build security.
Fifth - Emphasize psychic income. It costs nothing. It instills loyalty and motivation. Be very public about staff awards to spread the sense of security. And motivation.