Repetition works, but only if you repeat the right stuff - just like in music.
Practice makes perfect is a crock... All it will do is cement incorrect moves, if one is not careful. Normally, I would say 'isolate the problem - practice it outside of the whole series of movements - replace it in the series, and go for it.' However, we are not talking music, here.
Best I can do is to repeat my suggestion to do the whole double clutch thing
slowly. First thing on a very cold morning - with maple syrup for transmission lubricant - speed is your enemy, anyway.
Sorry for no supah slick Jedi mind tricks. All I have is a rather pathetic, old, and jaded sense of common.
Best.
Byll