To quote the presentation from the US Concealed Carry Association, I “hope you are never in the unenviable position” of dealing with a threat in extreme close quarters. For those who may perhaps be in the subway or similar extremely tight situations, USCCA has a great little video on drawing and shooting with no sights.
There are some great tips within (like canting the slide to ensure it does not catch on clothing) and showcases the disadvantages of using the same techniques from even a few extra feet away.