"Trials" question

To get shipment rewards you only need to play the game with the trials on. The achievements aren't necessary to get the rewards but are optional goals for you to work toward when using the trials. The number of trials you use increases the % chance you will get a shipment. But keep in mind that shipment rewards are randomized, so it might take a while to get the rewards you want. In addition, certain rewards like weapons and schematics are level gated and won't appear after a certain level (or only appear after a certain level). Those are listed on the trials page.

To increase your chances of getting shipments, you should play with as many trials on as possible.

The below list are the ones I use. I play on Casual, so the limitations of potions isn't that bad at all. In addition, I prefer to level slowly, so the trials related to exp fit my playstyle. Some trials are easier than others.

* Even Ground (enemies scale in level)
* Rest Easy (you lose focus if you travel to a camp -- I use this as I rarely use focus abilities while out in the world and also rarely fast travel)
* Rub Some Dirt on It (potions only heal 1hp -- useful if you won't be using too many potions -- be sure to disable follower potion use if you turn this on, since they will waste them otherwise.)
* Travel Light (supply caches {potion refills} are removed from the game -- I've experienced guaranteed shipments when using this during a mission)
* Take It Slow (earn exp at 1/2 rate)

Trials are best used on a new play, I think. Unless you're specifically going for the schematics (of which you can only gain one at level 27), the weapon rewards are mostly useless by that point in the game. You may find some use in the runes, belts, and other things.

The OP's post is specifically about getting rewards...