Tying flies can be a lot of fun, but it can also be frustrating. There's nothing like catching a fish on a fly you crafted all by yourself, but just getting that pattern cranked out in the first place can test your patience. Practice and experience will eliminate much of this stress, but those just starting out will have a lot of little techniques and tricks to learn in order to form a good basis. Simply getting material secured to the hook in the exact place you want seems like a really easy task, but some fibers can really shift around and cause some serious irritation. Thankfully, the solution is extremely simple—so simple that you may have already discovered this basic trick already!
In this picture, I'm attempting to secure a bundle of bucktail fibers directly on top of the hook shank. You probably notice that the fibers are not exactly right on top of the shank, but have rolled around as the thread was wrapped under tension. When tying in many materials—especially bunches of fibers like bucktail—you must first "trap" the fibers with a soft wrap before applying tension to the thread and cinching the material down. If you try to cinch down certain materials from the get go, the material will simply be pushed by the thread and roll around the shank with it.
To perform a soft wrap, I like to hold the material tightly between my thumb and forefinger precisely where I want it to sit on the hook. Before initiating the wrap, I make sure the very tips of my fingers are pretty much right at my tie-in spot. I do this because I like to use my finger tips to kind of "guide" the thread while performing the soft wrap to keep the thread in position. When you're ready, go ahead and make the wrap. It doesn't have to be real loose—just use a light touch to trap the material against the hook without pushing the material around the shank.
Increased tension can be applied to the thread as the first wrap is completed to help bind the material down. If the material is where you want it, a few more tight wraps can be made to lock the material in place. If the material isn't exactly how you want it, you can still manipulate it a bit with your thumb and forefinger to get everything inline.
With everything lined up, the remaining tight wraps can be made to securely lock down the material on the hook. I like to hold the material during this entire process to ensure it stays put perfectly while being cinched down. I will let go only when the material is locked in place and I'm ready to move on to the next step.