I find myself looking up these tutorials again and again, even if it is just to make sure I am doing something correctly:

Applying bias binding:  https://lladybird.com/2014/06/23/oal-sewing-sleeves-or-bias-facing/ (see the second 1/2 of the post)

Bra making (useful reading before taking on your first bra):
– Amy Chapman’s 3-part series on making a foam cup bra, the first part of which is here
– Lladybird has a 2-part tutorial in making foam cup bra, that references the link above, can be found here.
– Norma Loehr’s book, Demystifying Bra Fitting & Construction

Making continuous bias tape: https://blog.colettehq.com/tutorials/continuous-bias-tape-tutorial

Sewing a facing around an invisible zipper:  https://blog.colettehq.com/tutorials/tutorial-invisible-zipper-with-facing

Sewing a notched collar:  http://closetcasefiles.com/sewing-notched-collar-tutorial/

Welt pockets (specifically for Sewaholic’s Thurlows): https://lladybird.com/?s=welt+pocket&submit=Search