what works best with a double barreled surname?

[Ca Plane Pour Moi]

I think any length name would work.

Freda Hxxwell-Jones
Lucinda Hxxwell-Jones
Max Hxxwell-Jones
Maximillion Hxxwell-Jones

All sounds pretty good to me.

I may go with something like Lucinda or Maximillion, so your DH can have Luce and Max whereas they can have nice "big" names when they're older if they want.

[Ginger]

i'd go for a two syllable name with a double-barrelled surname.