If you want to set it so your variant attributes appear in a certain order on channel you can set this up on a channel by channel basis.
If you go into the integration that you want to change the ordering for, then go to the tab called "View Variant Attribute".
The first screen you will come across will look like this:
This screen shows you the variant attributes you have on that channel and how many listings are using those variant attributes.
You can set the order these display in drop-down lists within StoreFeeder so if you use certain attributes more often than others it would be worthwhile setting their display order higher to save time.
To set the order of your attributes on channel you need to go into the attribute by pressing "View", the screen below is what appeared when view next to size was pressed:
When attributes come down from channel they won't always be in order (with amazon the order doesn't matter anyway as they have their own ordering that cannot be overridden).
If you do need to order your attributes you can just change the display order number to rearrange, if you set a display order of 1 against "12-14" that would go to position 1 and everything else would shuffle down a display order. Below is the same attributes rearranged:
The display order is quite important for channels like eBay because if it's not correct it may be confusing for buyers so this is worth checking over.