I have made a choker and some hoop earrings for v4.2... how do I smart prop them?

Parent them to the head, for the earrings and neck for the choker then save each individual to the prop library. When you save you should have a message asking to save as a smart prop.

That isn't surprising.  The neck is a flexible 'soft' surface, and the choker
is a 'hard' object.  When the neck bends, the choker isn't going to expand
and contract automatically.

Easiest solution, I think, would be a little less choke.  In other
words, increase the X and Z scale on the choker until it looks good at
various non-extreme neck positions.

Alternatively you could build the choker as a conforming figure, but
that would be a LOT of work.

hmm..
well i have auto group editor...
and I'm ok at rigging.
This is not an extreme pose... thats why it confuses me.

All the same, the neck will change shape when it bends, and the choker will not. This is a problem with Poser, that at present although the body can affect the clothing, the clothing cannot affect the body.

If the choker is supposed to be hard and unyielding, then you either have to make it larger, or use a magnet to squeeze Vicki's neck.

If the choker can be elastic, then check "inherit bends of parent" when you parent it. This will avoid having to make a conforming figure - very useful for cases like this, were the prop covers only one body part.

Another thing you might want to try is to take the choker into the cloth room.