I’ve been knitting for about 8 years and I’ve never bothered with lifelines before even when I was learning lace knitting, but two colour brioche has defeated me, I’ve never had to rip out a piece of knitting so many times.
I have some Knitpro and Addi interchangeables with holes for a lifeline but they are bloody tiny - for those who use them, how?! I tried some 4ply but couldn’t thread that through either.
Also, it looks so uneven to me - will blocking help?