Good concept, but how do you know what God's plan for your life is?

Obviously asking him is a good start. And reading scripture - if my plans contradict what God clearly tells me in scripture, then my plans are not his.

Beyond that, questions like "should I take this job or that job" "should I live here or move away" "should I date this person or that one" are not always answered clearly.

Perhaps because God wants us to learn to make decisions for ourselves, as long as those decisions are not against what he has already told us.

Matthew 5
⁷"Ask and it will be given to you; seek and you will find; knock and the door will be opened to you. ⁸For everyone who asks receives; he who seeks finds; and to him who knocks, the door will be opened. ⁹"Which of you, if his son asks for bread, will give him a stone? ¹⁰Or if he asks for a fish, will give him a snake? ¹¹If you, then, though you are evil, know how to give good gifts to your children, how much more will your Father in heaven give good gifts to those who ask him!

To me the message here is "ask!"
It's okay to ask God for what we want.
The thing we should be doing is trying to line up our 'wants' with Godly things.
As long as we ask God for good things, the only reason he wouldn't give them is if he has something better in mind.
If we ask God for bad things, he probably won't give us those (If your children as for a poisonous snake or a loaded gun would you give it to them?)

Even Jesus asked for something he knew was not God's plan, but he wanted it so badly he asked anyway (and accepted the answer he knew was coming.) "..if it be your will, let this cup pass from me.."

As we grow and mature in Christ, we should want less and less of what is bad for us, and more and more of what we want will be what God wants for us as well. That's the process of becoming like him.
But it is a process, and until the process is complete, go ahead and talk to him about how you're feeling - that's part of communication!
Just keep your ears open for when he tells you "no that's not my plan, how about this instead?"