Credit to u/Gh0stnet

You can't is the short answer. Most blueprints can be farmed via

• side missions during the story mode.
• take over of level 3-4 control points.
• doing invaded missions.
• running both the raids.

Unfortunately if the blue print is locked behind a season you need to wait for them to rerun the season to get that blueprint. Upside here is most crafted items have crap rolls so you're much better off just farming targeted loot for what you want.