1. A two- to six-straw "loom" will work best. Decide how many straws to use; the more straws, the wider a bookmark you will weave.
2. Cut as many pieces of yarn as you have straws, each piece about five inches longer than the straws.
3. Thread a needle with a piece of yarn, draw the yarn through a straw, and lay down the straw with yarn showing at both ends. Repeat, to draw a piece of yarn through each straw.
4. Tie the tops of all the yarn pieces together in a single knot, without letting the straws slip off the yarn. Lay the straws on the table, side by side, and push all the straws up until they touch the knot.
5. Tear off a length of masking tape and tape the straws together. Tape across all the straws, just below the knot, and then wrap the tape around the back side, too, to hold the row of straws flat.
6. Cut a piece of yarn about six feet long. Tie one end of the yarn to a straw on the end of the row of straws, just below the tape. Weave the yarn across the straws—over one straw and under the next. When you reach the last straw, wrap the yarn around it and go back in the other direction.
7. Keep weaving until the whole length of the straws is wrapped in yarn. If you wish to change colors, cut the yarn, leaving a tail to tie to a new piece of yarn in your next color.
8. When you finish weaving, tie the yarn to one of the end straws and trim it.
9. Take off the masking tape. Hold the knot at the top of the weaving with one hand, and use your other hand to slide the straws out of the weaving, one by one.
10. Push the weaving up to the knot. Then, tie the ends of loose yarn together at the bottom of the weaving, with an overhand knot.
11. If you like, tie beads onto the yarn that remains at the bottom of the weaving before trimming the loose yarn.