Gretchen,

     You asked what I would do if I had one year. In my Freshman comp
course, I have three weeks. Because I can use the CASA program (which
requires that all students have access to a Windows computer), about 95%
of the students start that three weeks able to identify almost all the
prepositional phrases in any sentence. We begin with the
psycholinguistic model of how the brain processes language. See:
http://www2.pct.edu/courses/evavra/ENL111/Syntax/PLModel/Int000.htm
The model shows students that we will not be dealing with grammar in the
way they are accustomed to dealing with it, but rather that we will be
looking at the way in which human brains (including theirs) process
language. The "rules" are thus not arbitrary, but based on what the
brain does.

We then work with three or four hand-outs on S/V/C patterns and
clauses.  SEE:
http://www2.pct.edu/courses/evavra/ENL111/Syntax/SM.htm

The primary objective is to enable students to identify the clauses in
their own writing. Once they can do so (using the KISS approach), they
are also more attuned to S/V relationships (thereby decreasing S/V
agreement errors) Fragments, comma-splices and run-ons are clause
boundary errors, so the ability to identify clauses in their own writing
also helps students with these.
      Along the way, we discuss questions of style, primarily related to
clauses. We also discuss the implications of words per main clause, and
we end with the students analyzing a passage of their own writing,
including a statistical analysis. Some of my students, for example, find
themselves writing an average of nine words per main clause, whereas
others average 24. The class average is almost always close to 15. I
enjoy the approach because I can almost always find something positive
to say, even about the worst writers (who, for example, use advanced
constructions).
    If you would like to try the approach, you are free to use my
materials, but you will probably want to replace my exercises with
passages from your own students. I do not, by the way, believe in
sentence diagramming. If you try it with real students' writing, you
will quickly find that the diagrams become too cumbersome and complex.
Thus the KISS uses a simpler approach of bracketing clauses. As you will
see if you look at them, the exercises are simply triple-spaced passages
of students' writing. CASA can be downloaded from:
http://www2.pct.edu/courses/evavra/ENL111/Syntax/SM.htm
     Although I have been working hard to put this material on the net,
where it is available for free, it has come to my attention that not all
classrooms/schools are equipped to use CASA or the psycholinguistic
model. I can't do anything about CASA, but I could make the
psycholinguistic presentation available as a series of overheads. I
would, however, have to charge for the materials and time.
     Again, if you would like to try it, I'll be happy to work with you
directly, i.e., off list.
Ed V.