I love bruschetta. But not all bruschetta is created equal. There are a few components that have to be in bruschetta to make it good; Parmesan cheese, red onion, fresh basil and balsamic vinegar.
Some people try to get away with omitting some of those ingredients. Sure, it’s still edible, but it just isn’t really worth my calories if all of those ingredients are mixed in with some fresh tomatoes, garlic and olive oil. The measurement of each ingredient is sort of up to the cook. Everyone has a different capacity for onions and balsamic vinegar. But this is basically what I do for enough bruschetta to be topped on 1 baguette cut into 16-20 slices:

3 Roma tomatoes, diced, seeds drained
1/4 cup red onion, diced
1/4 cup basil, julienned
1 tbsp minced garlic
1 tbsp balsamic vinegar
2 tbsp grated parmesan cheese
1 tbsp olive oil
salt and pepper to taste

Mix it all the ingredients together in a bowl and let it chill for about an hour before you serve it. You can toast the baguette slices in the oven it you prefer them crispy. I like them soft, so I don’t toast the bread. I just slice it and top it.