I have found that in the stable you need to watch the parents of the horses you breed together. Certain parents give better enhancements to their foals than others.
Start with 2 new/bought Goldies - train them both in all 3 area's to level 14 & breed = 1 foal w/1 enhancement
repeat this to get a second foal
Take the 2 foals train them in all 3 area's to level 21 & breed = 2nd lvl foal w/2 enhancements
repeat this to get another 2nd lvl foal
Then take the two 2nd lvl foals train in all 3 area's to lvl 36 & breed = 3rd lvl foal w/3 enhancements
repeat to get another 3rd lvl foal
Take these two 3rd lvl foals & train them in all 3 area's to lvl 43 & breed = 4th lvl foal w/ 4 enhancements
repeat this to get another 3rd lvl foal
continue to train & breed the horses. As you find the better enhancements keep those foals a side to get better ones down the road. You're going to find that it takes about 7 to 8 levels per area to get another enhancement for the foal.