Given the way DSLRs work, it is sometimes the case that your lenses will need what is known as an "autofocus microadjustment." This excellent video will show you how to perform one to improve your lenses' autofocus performance.
Coming to you from Michael The Maven, this excellent video will show you how to perform an autofocus microadjustment (AFMA). DSLR lenses can sometimes miss focus in a precise but inaccurate way; in other words, your lens may focus consistently but incorrectly, missing focus in the same direction by the same amount most of the time. This might not be a problem if you only shoot at narrow apertures or with wide angle lenses, but if you shoot with a wide aperture for narrow depth of field, this can cause real issues. You might notice this, for example, if you shoot portraits and your photos are consistently focused on the tip of the nose instead of the eye, despite you having carefully focused properly. The first step is to always make sure your technique is rock solid, but if after having done so, you are still having issues, you might want to try this. Check out the video above to see how it's done. And if you need more help, check out this article.