Digimon World: Next Order's tamer skills are difficult to choose from, even if only because there are many options. To help you with your decision making, below we have outlined what we believe to be the most important tamer skills.
Digiegg Polish (Basic): This will provide more stats upon rebirth, which is critical to optimizing the potency of your digimon.
Defense Order (Commander): This defensive skill is great to have when you're experiencing trouble. It will allow you to mitigate 90% of incoming damage for a short period of time.
Second Order (Commander): This will provide a second skill slot, which is very important to being dynamic in the battlefield.
In addition to these three must-haves, we recommend investing in Movement HP/MP, Backpack, and Attack Order.