Like most people I used to get the orientation of the USB connector and the port wrong. However, once you finally notice that the USB symbol is always on the top of the connector things get easier. Better yet, this is actually stated in the USB mechanical specification (emphasis added):

6.5.1 USB Icon Location
The USB Icon is embossed, in a recessed area, on the topside of the USB plug. This provides easy user recognition and facilitates alignment during the mating process. The USB Icon and Manufacturer’s logo should not project beyond the overmold surface. The USB Icon is required, while the Manufacturer’s logo is recommended, for both Series “A” and “B” plug assemblies. The USB Icon is also located adjacent to each receptacle. Receptacles should be oriented to allow the Icon on the plug to be visible during the mating process.

So as long as you can see the USB Icon, it should fit first time.