For smokers who are not used to inhaling tobacco smoke, this can be a rough trick to try. Frankly, with all but the mildest of cigars, I cannot handle nor enjoy inhaling the smoke, so typically I use the French inhale when smoking a pipe, whose luxurious tendrils of smoke tend to be gentler on both the nose and the lungs. One must first master the art of inhaling smoke only into one's mouth, and then proper cheek control is needed. The smoke must escape your lips at the laziest possible speed, in languid, lethargic clouds. As this is happening, inhale slowly through your nose. This takes a little bit of practice, but keep at it.
French inhaling is useful not only for looking exceptionally hip, but also for fully enjoying the flavor of smoke. When tasting wine or tea, the taster always employs the olfactory faculties just as much as gustation, and this should likewise be the case with cigars, pipe tobacco, and other forms of smoking. One can either blow the smoke out through one's nose or French inhale it to get a fuller range of flavors.