Through crafting you can improve cow bells, doing this increases the amount of ability points they give when used.

Cow Bell

An ordinary cow bell will give 10 ability points when used.

They can be found from the Warfare Shop, the Boon Ship or occasionally from Targeting Modules.

Each cow bell can only be upgraded once.

Blueprints

The blueprint for cow bell crystallization will neither appear at the Black Market or the Blueprint Merchant. You have to obtain the recipe through a rare/epic blueprint.

Rare blueprints contain the recipes for Cow Bell Crystallization I and Cow Bell Crystallization II.
They can be found from X-Corp Markswomen, working Research Laboratory or occasionally from Targeting Modules.

Epic blueprints contain the recipe for Cow Bell Crystallization III.
They can be found from Aiden's strange journal, Outskirts Scavenging or occasionally from Targeting Modules.

Abstruse Crystals

Can be found from Crystal Entities, Outskirts Mining or occasionally from Targeting Modules.

Crystal Shards

Crystal shards are hunting drops from Crystal Entities.

The recipes to upgrade a cow bell require 2 null crystal shards. They also have 1 optional slot for any crystal shard.
The rarer the optional crystal used is the bigger buff the cow bell will receive.

Trades of crystals used shouldn't effect the trades of the end cow bell.