I used to struggle with picking seasonings too, but here's a strategy that I picked up from the internet somewhere:

1. Decide which basic flavor(s) you need
2. Pick an ingredient that will satisfy one or more of those flavors.

Here's a baseline "basic flavors" that should always land you a flavorful meal:

• heat (eg peppers, wasabe)
• acid (fruit, vinegar)
• salt (table salt, soy sauce)
• fat (butter, bacon grease)

But there's a few others that might come in handy, like:

• sweet (sugar, honey, fruit, many veggies)
• mint (thyme, rosemary, basil, black pepper)
• bitter (grapefruit, many veggies)
• savory (soy sauce, meats)
• whatever flavor alliums have (onions, garlic)

Of course, figuring out which basic flavors you need is still a skill to develop, but this two-stage process helped me a lot. Plus, if you're trying to stay traditional, then the second stage where you pick the ingredient may already be chosen for you. Mexican food needs acid? Lime. Italian needs heat? Red pepper flakes. Asian needs salt? Soy sauce.

TL;DR: Don't go straight to choosing ingredients you need, instead choose a basic flavor you need then pick ingredients that will satisfy that flavor.