To prepare a mari for stitching, it is generally divided into prescribed sections and then "marked" by laying down marking/boundary threads,  called Jiwari (in Japanese it translates to "areas or boundaries". Within temari it's meant as the marking lines for the design). Dividing the mari is done in one of several ways - using a paper strip and relational geometry, using a Japanese V Ruler for 10 combination division, for some using a calculator and tape measure, and for others doing it by eye - all depending on the division being created. The important centers, points & intersections are indicated by pin placements.

        Marking threads are usually metallic (but are not required to be), and usually a bit finer than what the design is stitched with (again, not required to be). The marking threads will often become an integral part of the overall design, so choose accordingly. On occasion, the pattern will direct you to mark in "invisible" jiwari - use a matching thread to the mari wrap. There may be other times that after the design stitching is  complete, the jiwari are removed.

        Marking the mari can be compared to "connecting the dots" - placing jiwari from appropriate pin to pin to create specific subsections on the mari that will be used to stitch the design. Use enough tension to keep the threads straight, but don't pull the pins out of alignment or damage the thread. As you place the marking threads, lay the thread purposely from pin to pin, in straight lines. Be consistent in placing the thread on one side or the other of the pins as you go, all throughout the process. This may seem insignificant,  but it's not. Pins generally have a shaft diameter of close to 1mm. By not being consistent in staying to one side or the other you are introducing that amount of error into where the marking thread is being placed. If we were working on a flat surface it probably would not mean much. But, temari are worked on spheres and the laws of spherical geometry take over. Don't run away as this being "deep math" - it's not. The only thing needed to remember is that when working on a ball, booboos grow. A little tweak here becomes a big tweak not too far later on. A 1 mm error in placing a marking thread way back here in the beginning can indeed make a big - bigger - difference down the road as you are working your design. Check out the illustrations in the "Little Things" of the TemariKai TookKit for thread placing.

       Do not remove the divider pins until you have tacked at least some of the intersections of the markings. Even though you should be keeping an eye on things for symmetry and accuracy as you go, check and adjust things as needed once all the marking lines are placed. You may find that angle templates, the original dividing strip, and/or a tape measure may come in handy. Remember, the object is to get things as even and accurate as possible - but, in reality no mari is perfectly round so there will be some minor "offs" (key words are "some" and "minor") - usually within 1 mm or 2 is fine. However - it's important to remember that the more involved the division and design, the more important accuracy and precision are when it comes to a round mari and accurate, sharp markings.

       Everyone has their own thoughts on "how much to tack". The point is no matter how accurate your marking is now, as you handle the ball through the stitching process things are going to shift around a bit. Tacking at least some strategic intersections is usually a must - such as major centers and corners. Some people prefer to do as little tacking as possible (and may just leave some of the marking pins from the division in the mari as they stitch). Others find a "happy medium" and tack between 30 to 50 percent of the intersections in addition to the major centers. Yet other people find that tacking all of the intersections is what helps them create their best outcomes. In reality, you will probably find that as you begin temari, you tack a lot - if not all - of the points. As your skill and confidence grows you probably will find that you can ease off a bit and concentrate on the major centers/corners. When you tack be sure to take a tiny stitch, on a horizontal orientation through the lines (ie, have an even number of marking lines on either side of the needle entry and exit of your tacking stitch. See the "Little Things" in the TK ToolKit). You tack with the same thread you used for the marking lines, or some people will use a finer yet matching metallic. Another option is to tack the marking lines (no matter what was used) with the same thread as you wrapped the mari in. This comes in handy especially if you are using a more "extravagant" marking thread, and/or a thicker thread.... and if doing this you can just move from point to point without having to bury the thread under the mari, since it won't show on the wrapped mari.

        It's worth noting that no matter how technically great a stitcher you may be or become, your skills will be negated if you don't take the time to hone your skills in making mari, dividing and marking. There is no substitute for taking your time and developing a good hand for neat and precise work. The most beautiful temari design can have everything distracted from it because of workmanship that shows haste, and/or lack of attention to detail. And indeed, these attributes are at the core of Japanese arts and life overall. To not take the time to work neatly, and continue to develop one's skill is dishonorable  (no matter what one may be doing). Skill in making mari and preparing it for stitching with dividing and marking is just as important as the actual stitching of temari. They cannot be separated.

       There is no set "path" that you must follow in placing marking threads as you are laying them down on any particular division.... most stitchers find ways to be conservative with thread without compromising quality. Japanese books will sometimes show various "paths" but there is no requisite other than being sure all the points are connected, intersections are sharp and neat, and the threads stay in place either through friction on the mari and/or tacking.