Here are a few of my more complex DONE's

cbr-syd
syd-bkk
bkk-lhr
lhr-bcn
bcn-lhr
lhr-aud
aud-mct
mct-aud
aud-lhr
lhr-ord
ord-iah
iah-dfw
dfw-mex
mex-mia
mia-lim
lim-mia
mia-lax
lax-syd
syd-cbr

And another:
cbr-syd
syd-bkk
bkk-lhr
lhr-cai
cai-lhr
lhr-ams
ams-mad
mad-lim
lim-cuz
cuz-aqp
aqp-lim
lim-scl
scl-akl
akl-syd
syd-cbr

And another:
cbr-mel
mel-sin
sin-lhr
lhr-abz
abz-man
man-abz
abz-lhr
lhr-mia
mia-clo
clo-mia (transit only, stopover not allowed)
mia-rio
rio-sao
sao-scl
scl-eze
eze-akl
akl-syd
syd-cbr