Every home cook should have a digital scale. They cost like $20. And yes, for subgrams, you can always estimate 'a pinch', 1/4 tsp, etc...
By weight is more accurate, almost never exceeds the max of a home scale and simply throwing everything into one bowl, taring the scale each time is quicker too.
Honestly, I haven't found many ingredients where you do it to the gram. A few like spices, salt or baking powder you just do it to taste or assume a tsp is enough, for that one item.