for general, ill always have one wen im defending, entrenching and having your light infantry on stand fire is very useful. and for attacking, ill have 2 generals, one to hide and the other to create decoys to go in tanother section of there territories.
and for spies, ill use them for defense. If i ahve no army wat so ever, ill make cheap easy spies and bribe there whole army with about 4 clicks. and if i do have an army, then ill bribe there artillery and supply wagons.
for scouts etc, i dont use them much, ill use them a little to counter enemy informers and ill use them to destroy a wonder, but thats pretty much it.