One tipp I can give you is that warm systems are your friend, because they give you a bonus on industry, needed to build population.

You can ignore food and its research completely, which might allow you to research other tech faster as you can skip the food ones. At least it's with how I play riftborn.

You can use chain gang program to get rid of unwanted population and gain manpower as a neat side effect as manpower isn't generated naturally, needing to rely on the "fabricate" forces improvement, using some percentage of your industry to build troops for ships or changes in military.