Tips for making rare drops less rare?

I'd like to forge Dear Lutemis (a CB), but it needs THREE Rathian spikes - and of the three Rathians I've hunted so far, none of them have dropped a single spike.

...wait a moment - on looking at the wiki page for the weapon, there are apparently two ways to make the weapon? There's "Create with" (materials) and "Craft with" (materials).

What's the difference between "Create" and "Craft"? Are there higher-tier weapons you can create from scratch, rather than having to upgrade an existing weapon?