There is probably a really simple answer, but I can't figure it out. I usually add them to the albedo maps, but when I'm just testing to see how they look this isn't very efficient and it doesn't allow me to change them around easily. Is there a way to blend just the dark colors of the AO map into the texture?
If you don't care much for physical accuracy then you can just multiply the AO map over your albedo texture. Quick and easy.
(I like using nodes but the UI can also be used)
If you do care, though, it gets slightly more complex.
This is the formula we will follow:
Diffuse = (Direct + Indirect) * Color
Direct means material node
Indirect is what is often called Ambient term It can be approximated as follows:
Indirect = AmbientColor * AO
If you want something a bit better to represent the AmbientColor you could make yourself a pre-convolved environment map (A.K.A. very blurred HDRI)
You might also want to have a UV channel that is used just for AO, separate from the albedo texture. If you do end up using one please, do not use the light-map unwrapping method, it will lower the performance of your game significantly.
Figured it out thanks to Atek. The trick is to add a seperate UV map for the baked ambient occlusion map as a light map, and then in the blend setting of the texture use soft light (or whatever works best for your scene) to blend both UV maps together. This video explains it very nicely: https://www.youtube.com/watch?v=63Zk2rmwDgc