I would like to say that with these technologies, be creative in how you use them. Think of how you can combine certain techs to create something. A simple example of a combination.

Forging + Propulsion +Combination = Guns. You can take it a step further by adding engineering/production in there to make more powerful bullet types, rate of fire and lots of other things.

The sky is the limit so think about how to combine things to get what you want.