I will describe a new construction of  (codimension one) co-oriented taut foliations (CTFs) of 3-manifolds. It follows from this construction that if K is  either an alternating knot or a Montesinos knot, then K is not an L-space knot if and only if every nontrivial Dehn filling on K yields a 3-manifold that contains a CTF. This work is joint with Charles Delman.