In early Israel, the adolescent days of the people of God, he led them by visible, audible signs: voices, fire, cloud, fleeces, talking animals, and prophets. That was the old way of knowing God's will. Now there is a new way.
"In the old days God spoke to the fathers by prophets. These days he speaks to us by his Son."
Hebrews 1:1-2
That is to say, God now leads us by the Spirit according to our knowledge of Jesus. We gain that knowledge by reading the New Testament, particularly the Gospels. At least 90% of all daily decisions are guided by what Jesus said and did. If we truly want God's will for our lives, we will believe what we find in Jesus.
What about the remaining 10%?
The Bible doesn't tell us what car to buy or what job to take.What now?
The answer is do what you want to do.
Isn't this dangerous? Don't we all know people who have made a mess of things by following their own desires?
The caveat to this dilemma should be obvious.
If we love Jesus and have his words and deeds in our thinking, we have his mind.
If we have a teachable heart, we will not go too far wrong. And if we make a bad choice, it can be redeemed. After all, the biggest mistake we ever made was rejecting God when he came to us in the flesh of Jesus and that was spectacularly redeemed. So don't worry too much about making a mistake and don't get stuck.
As Yogi Berra said, "When you come to a fork in the road, take it." Guidance comes when we are in motion. Trying to turn the steering wheel of a parked car is difficult and pointless.
If God wanted us to know his perfect will for our lives he would have told us to find it. He also would have told us how to find it. Nowhere in the Bible does he do so. Therefore,
we are in no way responsible for getting everything right.
When the Bible talks about God's will for our lives, it's always in terms of our character. For instance,
"It is God's will that you be sanctified."
I Thessalonians 4:3
As we get older and log some experience, guidance becomes easy - provided we have been paying attention. If we love God and trust him, he trusts us. After all, we are told to have the same mind in us that was in Christ (Philippians 2:5) and the Spirit is in us to will and do his good pleasure (Philippians 2:13).
So do what you want.