It must have been a woman who first said, "If it ain't broke, don't fix it."
Clearly, the speaker never had a truck she wanted to jack up, a car she wanted to hot rod, and certainly not a bow of any sort. All of these things beg for "fixing," even though they might already work adequately.
In this instance, we're talking crossbows. Like their vertical cousins, there's quite an array of accessories that can make a crossbow quieter, more accurate at distance and ultimately more effective.
Like anything else, though, a new accessory or gimmick won't make you a better shot right away. The best thing is time on the range, with bow in hand. Once you've gotten to where you can hit a 6-inch plate every time from 30 yards offhand (which can be accomplished in an afternoon with a scoped crossbow), it's time to accessorize.
Click image to see how to trick out a crossbow