So, one thing I learned last year with my middle-schoolers was that I don't have to complete a finished product every time. For example, when I want them to learn to write good topic sentences, I can provide them with a topic, teach them multiple ways to write good topic sentences, and have them just write different topic sentences. Nothing more during that lesson. You can do the same with the rest of the structure.
So:
Say you tell them we're going to learn 4 different ways to write a topic sentence. Have them fold a paper into 4ths. Teach them the first way in 30-second chunks...say, an occasion/position statement. Attach a gesture (or several gestures) to that particular type of topic sentence and its descritpion. Do teach-okay! until you feel they understand WHAT it is, then give them teach-okay! chunks to just come up with sample sentences that fit that model. Come back, share a few, go back to teach-okay! with their partners...repeat as much as you think is necessary....have them write down some of their favorites...move on to the next one.
Very little pencil-to-the-paper writing involved in a lesson like that, but LOTS of writing skills practice going on.
You can do the same for conclusions, transitions, main idea of a paragraph and details....etc... until they could write a multi-paragraph essay blindfolded without a pencil!
It makes a HUGE difference...when I finally let go of the thought that I must take them through the whole writing process every time, they began to make more progress.
Watch out...you may get clever sentences like, "When my teachers says it's time for math, I feel like putting my head in a giant nutcracker."