Simple, but it requires a bounce per futebol between touches, maybe even two bounces between touches per foot.
Focus on the left foot controlling 1 futebol and the right foot controlling the other. Try to stay foot-ball specific if possible. Touches should be belt or hip high, maye even chect high, to give the futebol a chance to bounce adequately allowing the juggler a time to touch the other futebol. Try to allow only 1 bounce between touches. Ideally the juggler should establish a rhythm which is accomplished by juggling both balls at equal heights, allowing only 1 bounce between touches, which would translate into equal timing of bounce-touch and therefore a steady pace of footwork.
Best if this drill is done on a hard smooth surface like a tennis court, basketball court or a driveway. Using a brasilian futebol is ideal because of the bounce and the size. Start by dropping the second futebol with your hand.
Once you get the rhythm and the touch try moving the futebol around, crisscrossing, changing foot-ball, touching it over your head to the other side of your body…..