We frequently are asked about cutting titanium. We've made parts for NDT (non destructive testing) as well as aerospace parts requiring precision tolerances and surface finishes. For EDM  information, refer to our article EDM and Titanium. As for machining, the best results come with most of the tools having a sharp edge and surface finish. Generally cutting speeds are low and our feeds are as course as possible, requiring proper tool geometry. Sometimes the geometry of the tooling will inherently create increased tool loads and work piece deflections. Because titanium as a lower elastic modulus, these deflections are greater than what we would see on a steel workpiece.  We use various high speed steels and tungsten carbide inserts.  We avoid some of the titanium pitfalls involving titanium chips welding to the cutting surface of the tool by climb milling, where the cutting tool tooth finishes the stroke of cut when moving parallel to the feed. Making sure the part  is properly clamped to avoid any kind of vibration or chatter is critical to our machining too.  EDM'ing Titanium has various settings specific to titanium. The biggest asset we have in EDM burning titanium is the ability to have custom burn parameters for the EDM with the latest digital EDM generators to eliminate the heat and 'bluing' effect (see the link to EDM and machining technical article).
Titanium is not a bad material to machine; the trick is knowing one of the twists that this aerospace alloy can throw at you!