Whatever you see fit, I myself prefer the 20/80 setup.
Depends on the rsi period.
Try using, for example, period 50 for rsi and it will never reach neither 70/30 nor 80/20. Rsi is "flattening" when you use longer periods. The longer the rsi period, the "flatter" the rsi is
That's true Mladen, I was talking about the standard 14 period by the way.
RSI standard Oversold/Overbought Are 30/70
This could be helpful