Compression settings vary greatly depending on the performance and recorded levels.
A good way to understand the settings-
Attack: Fast = less pick attack and high end, Slow= more emphasized attack and high end.
Decay/release: Fast= punchy, Slow= Smooth
Ratio: the higher it is the less difference there will between loud and soft dynamics.
Threshold: This is the wildcard that just depends on the material.
Usuallly you have 2 basic compression strategies. A high threshold and high ratio to just compress the peaks (limiting) or a low threshold and low-med ratio to compress everything and make it a bit more even.
You can even use two compressors to do both at the same time or in two seperate passes.