This idea would be lore-friendly, considering that (spoilers) Dragonrend was a shout crafted by mortals, and was meant to be used as a weapon against dragons.
My idea of how this would work would be that you could combine already-existing words of power in order to make your own shout. By combining different words, you would make a shout. By e.g. combiningsome words of "unrelenting force" and "storm call", you could call a strong wind that makes the enemies loose balance.
Each word would have the same power as it would have if you didn't know the other words of the shout (e.g. "Fus" would be a weak push). That would be good, since it would prevent people from making a shout that e.g. has the words "Fus Roh" that is equally powerful as "Fus Rho Dah, so Fus Rho Dah would still keep it's glory.
In order to use a word, you would have to unlock all the other words of the original shout. That way, it wouldn't be possible to just add a random word to a shout, that you have two words of, in order to make a better shout.
I suppose that these shouts would be created at some sort of dragon altar at the graybeards.
Do you think this sounds like a good idea?


Maybe a hybrid shout using one word from Unrelenting force would make the force part in the hybrid more powerful than one word, but less than 3. 
Is there a mod out like that?
...if not, I'm sure it soon will be now that Shout Crafting has been mentioned. 
