I like to use a dab of PetSilk Silk Serum (Mimimomo sells it on her website, toplinepet.com) on tangles. Then I use the tail of a rat tail comb to break up the tangle (always point and pull away from your pup), or I use the Chris Christensen buttercomb.
For general brushing, I use the ISINIS brush. If the boys are super clean, I use the Madan brushes.
Depends on the coat and the type of tangles, but sometimes washing and conditioning really well first helps. That is for what I call the "dirty tangles." Other times, you definitely want to fix things before getting it wet because bathing can tighten a tight tangle or mat.
It's all trial and error and lots of tools.
