Fusion.

[Vegeta]

Er.. there is only one fusion.

Fusion - This "fusion" ability combines the fusion dance, the racial fusion abilities and anything else that could be considered fusion. Two characters must learn the "fusion" ability to fuse. While fused, their base ki is equal to the combined base ki of both characters times two. The newest addition to this ability is the lack of restriction. Any races may fuse with any other races. If both characters posses a similar tier powerup (ex: SSJ and Transformation 4) they may use either of those powerups while fused. Other individual abilities (Genki Dama, Teleportation, etc.) can still be used. Different genders can also transform.

There is no Namekian fusion. Nonenonenone. There is only this fusion ability. The only exception is the Potarra earings that fused the two Trunks and that was pre-all fusions combined into this one fusion ability. There will never be another set of Potarra earings.

So if you want to fuse at all, you both have to get this fusion ability. Alright, cool.

edit reply to Piccolo:

So, does that mean I need to learn the fusion technique in a personal saga or staff saga or do I get it automatically for being Namekian?

You must learn the ability. You are not granted it for being of the Namekian race.

If I must learn it, once again, staff or personal saga?

It's not defined. You can earn it from staff or personal saga. But if you really want it, the easiest method would be with a Dragonball wish.