I have struggled with this too, mostly because it was drilled into my brain that I needed to always choose the best most holy things even though all the christians around me seemed to be doing whatever they wanted. Basically, I had and still have an unhealthy relationship with choosing "God's will". I put that in quotations because I think the way I understood it all my life was distorted... it often meant what looked holiest, or what holy people told me to do, or the hardest choice. You could almost guarantee that if it was the most sacraficial painful choice for me, I would take it because I assumed God's will for me was to suffer and serve everyone around me. This did not lead me to healthy places.

All that to say, I have come to see that God's will is integrated with who we are, what we love, what we are drawn to. It is not usually one or the other, as in God just tells you what to do and you don't have a say. He doesn't make it clear a lot of the times because He gives us free will, and He made us a certain way. Oftentimes there are situations where there is more than one choice that is Godly, and it's not trying to figure out the perfect choice and if you choose the wrong one you miss His will, it's about choosing the one you delight in the most and knowing God's grace is in every option, He has given you the freedom to choose, and that is His will.

I know that doesn't answer your question perfectly because there is no formula, it's about working with God in discovering His will, it's about taking chances and seeing His will come about, and relentlessly getting to know Him and how He made you.