Sorry, earlier I forgot to move the topic to the correct forum. I think I came straight from the home page and didn't even notice.
Harpdoctor wrote: Does develop with a full chord progression mean climbing up to the top end of the harmonica. In those old days I know I was a 1 to 6 hole player.
I'm not much into theory, but essentially I'm talking about structure.
When you improvise, you're freely getting into the groove and discovering new licks and rhythms, which is what you've done well.
To develop further, you could take those ingredients and create a signature phrase. Then you can create variations of that phrase. Finally you might put a string of them together in a particular order to make a full tune.
It's like a song which has a verse then a chorus and alternates between them. People talk about tunes having a I IV V (one four five) progression - the numbers refer to the particular variant of that signature phrase.
Of course, you can start with a standard structure, then freely bend the rules as you see fit.
I'm sure others here will be able to explain better than I can!