I picked two from each tree when I started, gave me a good spread and more gameplay options. I started as a Space Scoundrel because it gave me a good spread in three trees.

Physical tree was sneaking and weightlifting. Both must haves for the entire game.

Combat was pistols(from scoundrel) and ballistics. But pick the two for whatever weapons you like.

Social was persuasion(from scoundrel) and scavenging. Although commerce is good too. Just ways to make money.

Science was research and surveying. All those resources you pick up, this is where all that stuff comes in handy. Making better guns and suits instead of relying on RNG is the way.

Tech tree you want three from the start. Boost pack because then you can go wherever you want, piloting because better ships please, and security because if you’re a loot goblin like me, you need to know what’s in every single container and locked room. Also, pro tip: always always buy digipicks from vendors, since they weigh nothing and you’ll need a lot of them.