I've been through your trials and tribulations and know first hand an excellent inexpensive solution. I would skip using the preset WB's in the camera - they are all inefficient except possible the AWB in shaded outdoors or with flash - I had decent success with that . Don't waste time on the color temp settings unless you have a Kelvin meter for accuracy and they are not cheap. For indoor without flash a White Balance card is essential
Here's what you may wish to consider:
1)get a whibal card - the one I use is by Michael Tapes at: http://mtapesdesign.com/
the 36.95 one is probably your best bet. In AWB take your photo, then Set the photo as the Custom WB choice and your done. If the lighting changes repeat above steps. Note: this card offers more capabilities so be sure to read his tutorial.
2)And Shoot RAW, not JPG as JPG pre-bakes all settings into the picture. Shooting RAW will let you choose the white balance eye dropper in DPP. So you load your RAW photo with the WhiBal card, place the eye dropper on the WhiBal card in the photo, then apply to all photos from same session.
Hope that helps.
I do this all the time and the colors are dead on. Also note, if you shoot RAW, there's already a JPG embedded in the RAW file. The RAW is your Digital negative and the same benefits apply as if it were a film negative. You always have the unaltered original. I've played with the camera's color balance settings and that helped a bit but still to get accuracy nothing beats a a good white balance card.