I chose to use a zigzag chain and tassel for the tail end. Making the tail and tassels often seems to take as long as it does to make the bookmark, but tassels just seem to finish the bookmarks off better than a tatted motif. I do used tatted motifs especially if the bookmark incorporates a motif like the flower shape in the previous bookmarks. I used a five ring flower for the bookmark I gave away, but the 2 I just finished had tassels. In fact, I spent yesterday doing nothing but tails and tassels for these three bookmarks.
As much as tassels are a pain in the butt, they are an effective use of the thread left on the shuttles. I know some people use up the thread on their shuttles tatting little motifs, 4 ring butterflies or one ring flowers for decorating stationary, but I don't. I have only so many hours in my day and I refuse to spend them doing "make work" projects that serve no real purpose. On the other hand, I'm stingy and hate wasting anything, even thread. So using up the remaining shuttle thread on tassels, as time consuming as they are, satisfies my need to be frugal and at the same time empties my shuttles.