Disclaimer: I really don't know anything about crochet so this may or may not be acceptable in say, state fair quality competition pieces but it fits the three requirements I had, so that's what I'm going with. Oh, and if you're interested, my three requirements are that the star flower motifs stay together, that I don't have any extra ends to weave in, and that I can figure it out with my limited skills.
Basically, I'm joining the motifs as I go and I'm using the design of the motif to do it. At the point of each motif, on the final round of crochet is a "chain 3." This makes a tiny hole right at the points. When I'm working the final round on a new motif, I work the "chain 3" through this little hole on the finished motifs. There are two different joins and I treat them slightly differently. When I join the new motif to a single point, I work the second chain of the "chain 3" through the hole in the finished point. When I join the new motif to two points (as shown in the picture above), I work the first and third chain of the "chain 3" through the holes in the finished points. Just a side note, chaining the motifs through the holes does not allow them to move independently like two interlocking rings on a chain. Because the finished motifs have closed holes, I would have to pull the entire motif through the tiny hole (or the ball of yarn) to work them so they could be interlocking but could move separately. When I started this, in my head that was how it worked so it took me a bit of fiddling to figure out that while I could attach the chains the way I had planned, they would anchor each other together at the points instead of having independent movement. I'm sure someone who really knows what they're doing with a crochet hook already knows this but from the comments I've gotten on this project, it seems that I'm not the only knitter figuring out a bit of crochet.
So far this seems to be working and while this might not be enough of a connection for a worsted weight afghan (don't honestly know, I've never crocheted anything else before), it feels plenty secure for a fingering weight scarf. If there's an experienced crocheter who's reading this and feels that they can explain this better, by all means leave your explanation in the comments - you won't hurt my feelings.