I asked a LONG time ago for links to some folk's favorites and then I put them together on this page and promptly forgot about it for a year.  So here's some links gleaned out of one of the bramaking groups on facebook.  I haven't checked all these links, but here they are. 

Cloth Habits bra sew alongs. construction tutorials. https://clothhabit.com/tutorials-tips/

https://orange-lingerie.com/blogs/news/tagged/tutorials 

https://www.katmakes.com/blog/2017/8/1/changing-a-bra-pattern-from-full-to-partial-band-a-tutorial 

https://merckwaerdigh.wordpress.com/2016/07/14/how-to-add-elastic-in-a-bra-when-lycra-switches-to-scalloped-lace/ 

https://merckwaerdigh.wordpress.com/2016/04/10/creating-a-butterfly-back-in-your-bra/ 

http://alltheunderwear.sophiehines.com/sewing-lingerie-adding-accent-trim-into-seams/

A 5-part tutorial for Elan 645 bra pattern http://hooksandwires.blogspot.com/search/label/Elan%20645

And same for Elan 511 https://hooksandwires.blogspot.com/search/label/Elan%20511

And here's part 1 of her tutorial for Elan 530. (Links to next three parts are in the right margin.) These feel a bit dated (10 years old already!) but are well done. http://hooksandwires.blogspot.com/2010/03/elan-530-tutorial-part-one-trace-cut.html