I don't do fine segment work, I have neither the patience or desire to do so as I don't particularly like the finer pieces prefering to see the character of the wood rather than the design, although I do acknowledge the skill and dedication required to assemble them.
I relation to shop output segment pieces are about 10%
The pieces I do are more a matter of using up good offcuts that come my way rather than them end up on the fire, I do admit to enjoying the challenge of producing the segments with the minimum of effort by developing simple jigs or procedures that don't entail spending money on 'better' kit or a prolonged fiddle to get them correct.
For standard tapered segments I use a chopsaw fitted with a good sharp blade, it's essential that the blade and pivot axis is trued up in all planes so that the cuts are square to at least one face.
For slight adjustments to angular errors I use a bench disc sander, again attention to squareness of table etc essential.
Both items of equipment are lower/mid end standard.
Glue joints are as cut where possible, they are the most likely to be square and true and are more than fine enough finish for glue bonding.
The curved segments are bandsawn, no way with all the will in the world are cuts and angles going to be true enough for closed segment bonding, not in my hands anyway, and finishing is all done by sanding, the emphasis being on controlling the trueness to a face and flatness across the width of the curved surface. this I do again by hand with simple shop jigs. Pattern router of CNC would be the simple way but I'm not going to be doing enough to warrant that sort of expenditure.