Look in to the weather conditions at shipping location, UPS or FedEx hubs and locally ahead of time. Avoid extreme weather conditions. Winter storms can cause delays. Neither UPS or FedEx heat or cool their trucks. Schedule delivery day for when you can be home. Plan to be there the day after if your order is delayed. Scheduling your order to ship Tuesday and be delivered Wednesday is the best in my experience. Sellers are not as busy as on Mondays and it gives you several days in case of delays. Track your order, sadly I find tracking has gotten worse in recent years, with orders sometimes saying delivered before they actually have been.
Have your acclamation set up ready to go. Water heated and at a reduced salinity is usually best for fish. If your order was delayed in shipping receive the order and do you best. The fish have a better of surviving than if you return them. Most companies policies will give you full credit if they die and you tried to save them. Take a few pics if needed to document things if needed. Float the bags ASAP to normalize temp. Any fish that look distressed as you unbox should be the first to acclimate. I always check the salinity of the first fish bag I open. If the salinity is close or higher then you QT and acclimation water you can acclimate a bit faster. If much lower do a slow drip. I like to put the bags in a inexpensive plastic bin. I open them and start dripping water into them from a few inches above the bag to help oxygenate the bag. If the fish are really doing poorly I will gently hold them a little distance from a flow pump to help get water through their gills. I have seen fish survive 5 days in shipping bags so even if they don’t look well in the bag give them a chance! Once acclimated move into your QT. Good luck!