Well-designed Small Caps are more than just scaled-down versions of the Capital Letters. John Hudson gave some tips on how to make smallcaps efficiently in FontLab by starting with the capital letters as a foundation.
1. Scale the Uppercase letter uniformly to the desired height and put into the background mask layer. This will be the guide not only for height, but also for internal space. So, for example, the distance between the uprights of the scaled H will be the distance, inner edge to inner edge, of the uprights in the smallcap. This will produce smallcaps that are nicely proportioned relative to each other (presuming that your caps are nicely proportioned). [See Fig.1]
2. Paste in another copy of the cap outlines, and scale these uniformly for weight. I usually match the vertical stem weight of my smallcaps to my Lowercase, even though the smallcaps will be taller. [See Fig.2]
3. Use the FontLab ‘Interpolate’ function to reduce the height and width of the weight-adjusted caps to match the height and internal space of the mask. This should be done in two passes: one for the y-direction and one for the x-direction. Be careful to maintain weights. [See Figs.3-6]
4. Test and fiddle. [See Fig.7]