Some additional thoughts, some of which you may have already considered:
- Mixed lighting can always be tricky since positioning of the card and then the subject can be critical. If the highlights are coming from one light source and the shadows are being illuminated by another, for example, then just about anything you do is going to be a compromise - at least as far as global white balance is concerned.
- There are white balance cards and filters available that are a little bluish. These will result in a warming balance. If you consistently like a warmer shot and prefer to not have to adjust the color temp controls in LR, you might want to add one of these to your toolkit.
- Some of what you are seeing may be a result of the camera profile you are using in LR. If you are using LR2, you might want to invest in a Colorchecker chart if you haven't already and use Adobe's DNG Profile Editor to create a custom profile for your camera. You can shoot a primary profile using dual-luminants (daylight and incandescent). You can also shoot specialized profiles under mixed or fluorescent lighting if you like. The Profile Editor is pretty easy to use. Some people complain it doesn't use enough sample points but it helped improve the color accuracy on my camera quite a bit.