A paragraph map
Here's a quick tip I use to help writers who are stuck on a couple of paragraphs. If the logic just doesn't seem to work, try mapping it
Take this paragraph:
Model 1 says… However, this does not account for A. Model 2 says… Yet, this neglects the effect of B. However, Model 3 accounts for B. But it fails to produce C.
Now, we can see where the problem lies. Without the topic sentence to impose discipline, the connectors cannot create coherence. Instead, they simply reflect the writer's stream of consciousness. For readers, this is just a lot of zigzagging.
To fix such a paragraph, first decide what type of point you want to make; then phrase your topic sentence to make it; and finally, choose the right connectors to flesh out the point. So for instance, if you are making a causal point, your topic sentence might say something like "Because X matters, Y is increasing." Then, the natural connectors are probably ones like these: since, as a result of, therefore, thus. Similarly, if your point is to compare two things, your topic sentence might say something like "In general, A is higher than B" and natural connectors would be ones like these: similarly, like, in contrast with, not only but also.
Once you've mapped out individual paragraphs, create connections between them through topic sentences, so that skimming readers can see your storyline at a glance.
Post by Varanya Chaubey Image of map on blog cover by http://maps.bpl.org [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons