Arrow manufacturers list arrows by spine, or the stiffness of the shaft. Slower bows impart less flex on an arrow, so they need less rigidity, or spine, to fly true. Faster bows need a stiffer spine. Arrow manufactures all have calculators on their website to determine the correct spine. Third-party software like Archer's Advantage is also popular with pro shops and hardcore shooters. Factory-fletched arrows work well in most hunting situations, but there's a pleasure in building your own arrows, for sure. I'm partial to helical fletchings and the Arizona Rim E-Z Fletch makes this, well, easy. Likewise, common 100-grain broadheads do the job in most hunting situations, but I'm partial to 125-grain or more. Wherever you land, make sure to weigh and spin-test all your arrows. Toss out any that spin erratically or deviate by more than 10 grains. Number each arrow with a pen on the fletching. That way if you have an inconsistent flyer you can easily identify it, and not take it into the woods.