To reduce latency, make sure the USB mic is the only USB device plugged into your computer. Using multiple devices (connected) can slow down your computer.
Some recording software will let you reduce the buffer size which will help reduce latency. Audio programs typically use a lot of computer memory so be sure to have plenty of RAM to speed up your computer's performance. If you are on a PC, you can also download an ASIO4ALL driver. This driver reduces the latency in your computer.