This skyline photo is either very complicated or fairly simple. It's up to you.
Are you inclined to paint the buildings one at a time or all at once? In the background the buildings have merged into a single mid-value shape. Can you find a common denominator like that for the buildings in the foreground? What if you painted the entire foreground a vey light but intense yellow? Then you could begin to bring in a blue grey that is a little darker than the yellow, and then a darker grey as verticals and horizontals that begin to separate the buildings from each other. Put off taking inventory until you need it, if you ever do. That way the odds are better that you'll recognize the moment when you have done enough.
Here is anther skyline image that would benefit from this approach.
And here's one where most of the work of combining adjacent shapes has already been done:
If you do this one, try one of the others, too, and have fun