Hi
It is very much personal choice and experimentation. My spindle gouges are around 35 degrees with skews being a little longer. Bowl gouges are 65 degrees but these are a very contentious issue. I've had one professional turner tell me to my face that 65 degrees won't work and another tell me he uses an 85 degree regularly for some difficult cuts so take from that what you may.
Some years ago everything was 45 degrees and that was that but it is now recognised that most angles work, just some work better for some than others!
HTH and doesn't confuse further!
Richard