*Note: This is not a right or wrong way of doing things topic. How God leads people is always different; this is just how we do ;)
Should we take this job? Is this the church for us? When do we try for a child?
Big questions.
Simply, we make our own plans (within a Biblical worldview, of course), while we ardently question, seek, and pursue the LORD in prayer about the situation at hand (which could be days or years).
Here is where it is dire (to us) to wait on Him, be sensitive to His Spirit, and know His voice.
If He chooses to do so, then this is the part of the process where He intervenes and leads (dreams, visions, a spoken word, others, a verse... there are oh-so-many ways He uses). However, your spirit will always know when He is giving you direction, even if your "sign" sounds silly to others. Deep in your heart, you know when the I AM has come. (If you don't know, keep seeking and asking; He won't scorn you and laugh because "you missed it!")
Let's say there is no "sign." How long do I wait? Well, what we typically do is wait until we have to make a decision or until we feel like we have to make a decision.
He knows our finite deadlines. In our lives thus far, He either speaks before we must decide or He doesn't. And when He doesn't? We fall back on and implement our own plans. This is not bad or wrong! God has, can, and does frequently use and work through our plans. [Our plans being godly and conforming to the Word.] Our plans often seem to be His plans; we just seek His direction in case they are not His plans this particular time, and He has a different direction for us to go (Prov. 16:25).
We can make our plans, but the Lord determines our steps. ~ Prov. 16:9