Rambling when writing fiction

A problem I find I have run into a lot when writing fiction is rambling. I often start a scene not knowing where it is going to go. Sometimes this works out to great material. Just as often the scene I write doesn't have any meaning or soul, or worse any conflict, at most a strict logical "okay I guess that isn't strictly speaking contradicted by anything that came before." The scene lacks coherence.

This is worst when I write a scene in parts over multiple sessions. Lately I have been writing fiction in chunks of one to five sentence at a time since that's easy to keep up with. It works, I am able to keep up with it, but I find I am frustrated because I can rarely connect with the character and find the conflict (emotional need, want, obstacle) in the scene. Explicitly sketching out the character's emotional need, want, and obstacle seems like a bad idea in that if I don't already know what it "has to be," then writing it down is likely to result in a trite "easy answer."

Maybe it is useful to try and write toward a conflict each time until I find one. Try to answer questions like: What do they need? What do they want? What makes things so hard they have to resort to extreme/unusual (for them) measures (the obstacle)? Go down the list. If any one of those questions isn't answered — try to write a next sentence that gets me closer to answering that question.

Worth a try, I guess?