I think its also important to note that you have autonomy in your own life/space (space defined as spirit/aura/body and lifetime) and that while you may have guides hanging around, you have seniority over them in your space. You can end, change or create new agreements with guides at any time.
Just because you've got a guide hanging around trying to give you advice from like, 10 lifetimes ago, doesn't mean that the agreement you have with them is in present time; that particular guide might be operating on information appropriate for 10th century France - but if it has not experienced life in a body in the 21st century, it might not have the appropriate information.
Just because an entity is in the spirit realm doesn't necessarily mean that it "knows" more than you do. Its just at a different place in it growth.
As Erin and others have said, its trial and error and active engagement. You can cultivate very in-depth, useful relationships with your guides. But it takes time and openness.