Step 1 Siteswap 23[43]03. Let us start from the pattern in Lesson 11 but replace the [4x4] throw with [43]. This will be accomplished by arranging the balls diagonally in your hand. As before, avoid moving your fingers when throwing.
Step 2 Siteswap 23[43]0 can be easily mixed with the cascade and other async patterns. Another example is 23[43]0441
Step 3 Siteswap 23[43]0 often has a moment of inactivity when all the balls are held in hands. This can be avoided by adding a "secret extra throw", that is, making the 2 active by throwing it over the incoming ball. This can also be written as 3x4x1xR[43]0 where R is needed to indicate that both 1x and [43] are for the right hand. The latter link can be used as another excercise to get more repetitions faster.
Step 4 Siteswap 23[43]03 with active 2.
Step 5 Siteswap 23[43]0333 with active 2. The pattern mixes easily with async patterns and multiplex patterns.
Variant You can replace [43]0 with [31]3 in any pattern. Throw [31] as you would throw a vertical multiplex [33], but then slap the lower ball back in the air with the palm of your free hand.