SPI is not very different from I2C. To enable a slave device, we need to pull the CS pin low and after our read or write is complete, just pull the pin high again. This will disable the slave device.
Starting with the simplest one i.e using the POLL method. The data is Received in blocking mode i.e the CPU will block every other operation until the data transfer is complete. This method is good to use if you are only using UART and nothing else otherwise all other operations will be affected.