Why Not

This pattern was the first pattern with a heff that I learned. It was quite a big step for me at the time, so I would recommend starting with the 5-club why-not and some other patterns/tricks one that may make beginning with heffs in patterns a bit easier.

Patterns to do before this one

one-person 441 (should get 50-100 catches)
one-person 4 club fountain ( should get at least 10-20 catches)
Jim's 2-count - This is also a compatible pattern, only two throws are switched
5c why-not
4-count with 441 instead of 3 selfs
3-count with 42 instead of 2 selfs
9-count why-not (the why-not like pattern compatible/based on Jim's 4-count

Why Not

Siteswap: 77862

77862

Animation and diagrams on passist.org

Sequence: A starts with 4 clubs and has straight passes, B starts with 2 clubs and has crossing passes.

A 2|2: P S P H Z
B 1|1:  H Z P S P

P=pass

Z=zip

H=heff

This start with 4 clubs for A has the advantage, that A can throw the complete (first half) sequence of the pattern plus one pass before running out of clubs. So if B only catches all passes without throwing to A, A can get used to the new sequence without the stress of having to catch incoming passes.

Juggler A should also do this "dry run" starting from the left hand, to get used to both sides of the pattern. This is of course mostly an advantage when B already knows the sequence. If B cannot do why-not well, it is recommended that B juggles a compatible pattern they are comfortable with like Jim's 2-count (see below).

There is an alternate start, where each has 3 clubs:

A 2|1: P H Z P S 
B 2|1:  P S P H Z

Here, B has the start into the sequence that A had with the 4-club start above.

Color coding: Three Clubs always do the heffs and passes, the other three clubs do self-zip and pass. So you could color-code the clubs that do the heffs.