You don’t have to use it, but you can check [1.1] Heavy’z Casual Loot Filters for all Classes v4.1. He explains stuff fairly well for you to get a grasp on how things work.
Your main tactic for creating a loot filter should be to basically hide everything and then only show the stuff you want. And you usually don’t want to show only perfect items (like items with 4 affixes you want), but rather items that have, for example, 2 out of 5-6 useful ones, which you can then craft/improve.
When at lower levels you might even just be happy with one affix.
Basically the best strategy is to start by hiding less and making it more strict as you get better gear.