Rule of thumb is that the voltage across the emitter resistor (as set by the base bias voltage) should be between 0.5 volts and 1 volt. This is just a hand-wavy rule of thumb so, if you decide on 0.5 volts then the base needs to be set at approximately 0.7 volts higher i.e. 1.2 volts.
The whole point here is that you usually want maximum swing of signal on the collector and any standing dc voltage across the emitter resistor will eat into this requirement. Here's the general idea: -
I've chosen bias resistors that set the collector at about 4.5 volts DC on a 9V supply. The voltage gain is approximately 10 (Rc/Re) and, if you look closely at the bottom of the blue trace (collector voltage), it's starting to crash into the voltage on the emitter resistor. This is starting to clip the bottom peaks because the BJT is entering saturation (collector-emitter voltage less than about 0.1 volts).
When saturating the hFE of the BJT reduces rapidly and you get distortion.
Hence you want to keep the emitter voltage reasonably low to maximize the undistorted collector voltage swing.