This is probably old news to most of you long-time bikers, but don't overtighten the steering head bearings, or your bike will exhibit some very strange handling characteristics, especially at low speed. Lots of wobbling and weaving. It is a delicate adjustment, finding the sweet spot between too loose and too tight.
My W650 head bearings were slightly loose, and I've tightened them just a touch too tight. However, it is close enough that I'll ride it out. If you haven't grossly overtightened them, they generally work themselves back to where they need to be.
Bob