This is what I did and it still does not work but you can see my steps -
1) I created a parent product called shirts -
2) I created two child products from the shirts product and called them , small and large .
Thus I have now three products.
3) I created a custom field using the Generic Child Varient and called it size of shirt
4) I went back to my parent product and >> custom fields and chose two custom fields I just created.
5) I then went to the myparent >>product information and there appeared two child products within the parent product.
6) I then went to the front page and looked at my product -
7) - yes I could see the drop down boxes and the costs >> I thought I only needed one drop down option (as you can see in the image I have two)??so I went back to the parent product and deleted one custom field hoping that I would end up with one drop down box and two options.

What happened was that I then ended up with just one varient small shirts and one button - that was no good.
9 ) I replaced the varient in the parent >> now back to where I was. a product with too many buttons and options.
10 ) Besides the prices adding and driving me crazy - I then tried changing price option in the child products(inside the parent product) , the custom fields, and then in the actual chilld products themselves.
Then I took all the T shirts placed them in a pile and jumped on them. ( or I thought If I washed the large T shirts in hot water)) they would all be small and I wouldn't have to sell big ones or use varients.)
* I only used T-shirts as a test - I do not sell them at all.
I have put up images of each of the options I spoke of - I know they are not correct but at least it might create a discussion. or others might try for suggestions.
10)
[attachment cleanup by admin]