I've been into photography for more than a year now and I've learned a lot of things through many of my mistakes. One common mistake by amateur photographers is setting the wrong white balance. One way to find out if your shooting photos with a wrong white balance is to check the white areas on your photo. If those white areas have colors in them, your white balance setting is off. The camera's auto white balance usually works most of the time. There are just some instances when the camera can't detect it properly. Mixed lighting tends to confuse your camera's auto white balance.
The easiest way to set always have the correct white balance is to set it manually. Most DSLR can set the white balance manually through a button. All you need to do is locate and press the button in your DSLR that sets the white balance. You then shoot it at any gray object to set the white balance. I usually use a piece of tissue or a white hanky to do this.
There are still ways to save photos with a yellowish or blueish tone in it. If the color isn't that off you could always set it to auto-level in Photoshop. Photos with deep yellow or blue tone can still be edited using photo filters, and selective color. You can also fix this problem using the color balance in photoshop.
To prevent this from happening it is always a good practice to set the proper white balance. It will help you save countless hours of post-processing late on.
I hope these tips will help you in shooting your photos.