Oh, it's a huge effort! These bodies meet and discuss what the proper spelling of words should be, or they make up new words, and then they publish those guidelines for journalists, authors, and anyone who wants to speak "properly" to follow.
It gives the language a good balance between spelling and pronouncing - that's why you can pronounce most words in German and Spanish exactly how they are written (I think there are very very few exceptions, if at all). But this comes at a price of losing ability to track meaning some times.
Sometimes it is not going so well, for example, look at the tumultuous German reform of 1996.. https://en.wikipedia.org/wiki/German_orthography_reform_of_1...