I do not see where the OP mentioned RTW, just international multi-segment itinerary.

Most of the time, I try to "nest" segments... for example, I never want a changeable or refundable segment attached on the same ticket as a non-refundable segment, because ultimately, it greatly complicates changes and refunds where one would be entitled to one.

If some or most of the segments are refundable/changeable, they can usually be booked separately without much of a fare penalty, if any.