I just keep the WB on the camera set to "daylight" all the time.
For astro, that's fine and you're processing pretty heavily anyway, stretching, playing with levels and curves a lot.
For normal photography, I have a white balance card that I try to shoot in the same light as my subject first. Then when I'm processing, I just use the eyedropper and click on the grey card to set white balance. After a while under different light conditions, you get used to what colour temperature and tint adjustments need to be made to correct the white balance shift. Actually, I haven't used the white balance card for a couple of months.
This is the one I got -
WhiBal from RawWorkflow.com.