In article . com,
says...
I am laying the same glueless laminate flooring in adjacent rooms, I
understand that I need to use an expansion strip in the doorways.

In the first room I started in the opposite corner of the room working
towards the door.

When I start on the next room should I continue from the doorway (i.e.
continuing working in the same direction) or start on the opposite side
from the door again where the longest straight wall is and work towards
the door again ? (so that the flooring is laid in both rooms working
towards the common door ?

Always start along the longest straightest wall. I'm not sure what
difference you think that will make to expansion gaps.

P.S. Also, how important are the expansion strips, should I put one in
the doorway of the built in larder too if I'm laying flooring in there
too ?

Probably not needed if you're leaving a gap around the rest of the
larder.