Great sketch! I like the little details you add, like the swing and in the sunset piece, little silhouetted plants.
Honestly I don't even remember attempting to draw an entire tree, but I have sketches of close-ups I did last year.


I think the thing with drawing trees, is to vary the line texture and shape, like thin, thick, etc. by using the side of the pencil or the tip of it. That's for expressive lines anyway, to give them character. This was something I realized in retrospect, so I didn't do it so much in those pictures...
For entire trees, it's helpful to group the leaves into clumps, then adding detail within those clumps. Only bits and pieces of branches showing amid the leaves is fine if it's spring or summer. Just my $0.02.
Edit: Why does everything show up so big? I have no idea how to resize??