My "want to main [Mag] without investing in her until I can get her prime" build.

As far as the build goes, the main damage tool is Magnetise. With the extra range and the augment, it should be able to create very large death orbs to gather up enemies, and keep them stunned, as well as create cover. Also, Crush is very useful for overshields (which spreads to teammates within range), as well as armour stripping. It can also be used when [Mag]'s shields drop as a panic button to get some shields back, and momentarily stun nearby regular enemies.

For weaponry, projectile weapons tend to really shine on her because of how Magnetise holds and spreads out damage. I used the bow [Dread] in the early game, and now Naturak after completing the requisite quest for it, which I've had a lot of luck with!