First you buy or craft the base ebon armor.
Then you specialize it with an aptant and change it's color with a pigment.
Ebon Pigment(black) and Furia Pigment(red) are each others dark/light opponents, while Ebur Pigment(white) mixes both sides and gets higher evolith slots. (Yes, Red handles Light elements while White handles a mix of Dark and Light)

Aptants are relatively easy and can be obtained solo or lowman.
For pigments you usually want ebur, which is a pain to get even at 90.

When you got your prefered armor, use [Mordant 75] to etch the slots with synergy. Each slot requires a new synergy, but you do not lose slots (or installed evoliths) already carved. Slot size is random, so you want to get a smooth synergy to get the highest chance of a capped slot. If the slot is too small for your taste, use a [Revertant Singulus] to remove the last etched slot, or a [Revertant] to remove ALL slots.

You have to choose an element for each slot, so make sure you choose the right one for your evoliths.

Adding evoliths is easy. Just synergy the armor and the evolith, and it'll pop right in the proper slot.

You can only add slots to certain weapons and armor, and only if they are 'clean'. So no signatures or existing (FoV/scenario) augments.

If you want to read more about it, go to http://ffxi.gamerescape.com/wiki/Category:Synergy .
For an overview of what gear and slots you can etch, go to http://ffxi.gamerescape.com/wiki/Cat...ng/All_Recipes .
Finally, to see all different evoliths and where to get them: http://ffxi.gamerescape.com/wiki/Evolith

I'm one of the major contributors of those pages, so feel free to ask me about details. If you are on the Bismarck server, I can assist with synergy as well. (/tell Kristal)