1. Ask the GM to randomize the artifact.
2. See what artifact you got. Then, build your character around it. Let's say you got the Gigamech.
3. Since it's the Gigamech, you'll be a warrior.
4. First, make sure you have at least 15 Charisma. Why? Charisma is one of the few stats that are actually important at certain values.
5. Choose a specialty that buffs Strength or Charisma.
6. Choose a skill for good melee combat. You can either immediately spend experience points to improve it or leave it at the basic level.
7. Choose a persuasion skill. The most obvious option is an element that deals damage or provides HP. There's no need to overthink this choice. But the most interesting part, of course, lies below... and has a much greater impact on the game. Nevertheless, I don't recommend trying complex persuasion skills right away.
8. Equip default gear. Use crystals for HP and damage as consumables, and put food in the extra bag.
9. If you have any experience points left, spend them on Charisma and Strength.
That's about it. But keep in mind that battles aren't the most frequent occurrence in this experience. A talkative, charismatic character is usually more beneficial than a top-tier warrior.
And most importantly: you can always fail miserably, even with a perfect build, or succeed for a long time with a ridiculous build.