Next, you blow air steadily through the straw while moving your hovering straw around, back and forth, or in one continuous direction until the paint/ink no longer flows and/or you are satisfied with the pattern. Take care not to hyperventilate :)
Liquid watercolor paints flow nicely on watercolor paper. Liquid acrylic paints can be manipulated on light-weight card stock but seem to dry quickly during the process.
There are some interesting technique ideas worth viewing on various YouTube presentations.
Participants may use colors over colors. It is also okay to accent the flowed paint/ink design(s) with rubber stamps, pen lines, markers... but let's save collage for another swap.
Make 1 - 4 post card-sized pieces to exchange with an assigned swap partner.