Many new players try to get their steel from expedition. The primary use of expedition is to get food and water; dismantle is a much better way to get steel!

An idle ship earns only 1 GEM per income phase, and scores ZERO points at the end of the game. (Unless you're playing a certain advanced hub.) A big burst of steel now is much better!

VP tokens are good; 40 VPs will end the game, and you should try to get close to it in almost all games. When in doubt, take food / water / steel over a VP, and a VP over 2 gems.

The more resources / VP you get from an income turn, the less you need to care about GEMS, because all running out of GEMS does is force you to take an income turn.

It is possible to build an engine so strong that an income turn is stronger than a ship action.

Fill your sectors! Empty sectors don't provide benefits, and residents score a lot of points. Generally, Expedition is a better way to get food and resources, and transport is a better way to convert resources into residents. Occasionally it is worth taking humans with expedition, or buying resources with transport.

Many new players tend to build all the level 1 sectors first. The most powerful effects are in level 2 and 3, so it's usually better to think of which one you want early and build directly towards it.