What little I know about writing transitions

Yesterday evening I spent a lot of time hammering out some new lead lines for various sections of my jazz arranging project. This is probably the longest piece of music I've ever written, so I'm finding it a bit difficult to keep my eyes on the big picture; instead, I'm discovering I have a tendency to "chunk" things too much, such that each successive section of the piece follows right after the one before it with very little transitional material.