Good so we know this much xD now lets make it clear. All in the end chakra is just chakra, there is no wind chakra or fire chakra. We use the terms to refer to the activated natures with the help of our chakra. Fire, wind, water, lightning and earth are chakra's natures. As such one can have more natures though it takes time to develop the ability. As we're able to use more natures and reach new heights with the use of our chakra, it develops. In a manner us sage's chakra is more mature then that of a Sannin, much more mature.
Nature transformations work by molding your chakra and drawing on an elements characteristics and immitating them with your chakra.
Water Release
By making ones chakra flow like a liquid by manipulating the chakra to rapidlyu move around which immitates the initial speed of the molecules that allows water to flow so freely.
Fire Release
the user manipulates their chakra's initial temperacture causing it to increase to the point of ability to burn or incinerate with use of friction as a means to activate and create heat.
Lightning Release
The user manipulates their chakra to become static and move around like a current of electricity by manipulating protons and neutrons to generate energy and with manipulation of the chakra to turn that energy into an electrical current.
Wind Release
The user manipulates their chakra into two different currents which collide with each other and rubbing against one another with intense force that forcibly sharpens the two currents edge increasing its potency aswell as manipulating it to cause collisions with multiple currents that effectively causes explosion of energy which practically manipulates a strong blowing wind or gale force.
Earth Release
The user manipulates their chakra so that it becomes strong and hard increasing its density and mass which immitates the structure of earth and mud
with the combination of the water and fire chakra you basically manipulated the fire chakra to slowly regulate the temperacture keeping it low enough that it doesnt initially evapourate but not low enough that the water would exstinguish the flames, which allows for the combination of the two perfectly, basically boiling the water to a certain level and thus creating a perfect syncronization.
I hope this was what you wanted , the concept of Yin-Yang is a new area for me so its not the best of knowledge or understanding
Yin/yang the 6 basic (which is much more advanced then any other nature xD) is a whole new feat where we control yin and yang (you know the concept) natures of it. Now as such the 5 basic could also be divided in to Yin and yang elements.
-Now divide the 5 in to yin and yang natures and explain why which elements fits in to the category you chose.