Whether or not you’ve written everything in your current draft or work-in-progress “in order” (which could mean either the order it will take on the page in your final draft, or the chronological order of the primary narrative), there are likely to be continuity jumps — chapter or section breaks, places where you move back and forth in time or from one point of view to the next. This sort of structure creates both relief — a natural time to take a break from a plot line — and suspense for the reader. In so doing, it leaves narrative gaps. You can just leave them, but an excellent technique for transforming the sense of vertigo a reader may feel when leaping across your narrative gorges is to bridge them with what I think of as link stitches.
The French Link is a book binding stitch for connecting signatures that results in a gorgeous patterns of crossed threads. Narratively, the idea would be to be mindful of the endings and beginnings of each section of your book and carefully make sure that later sections pick up and continue the threads you have started and left hanging in prior ones. Chapter 5 need not pick up the timeline just where Chapter 3 left off, but if there was something going on left unfinished there (a letter sent, a vase broken, a call dialed), you might want to include a reference to it — possibly only a very brief one — and how the matter concluded, even if you have moved forward much further in time. If you leave such threads dangling, it frustrates the reader. If you connect them or tie them off, it pleases the reader. You decide.
You may want to develop a rhythm to your links, whether it’s rigorously regular or a little more complex and even erratic — say every other chapter for a while, until a new thread starts, which eventually gets brought into the pattern. You should be conscious of the opportunity and make a decision about using link stitching wherever breaks or white space occur, but chapter or larger section breaks are the most likely spots for this kind of linking. One caveat: if you make your links too regular or overt, they may seem clunky, obvious or facile. If you deploy them deftly, you will create continuity and a wondrously subtle structure in your text.