On position sizing and 'getting the feel' for it.

Still trying to wrap my head around position sizing. I understand the math, the 1-2% rule, but sometimes I feel like I'm either over-committing to a setup that's 'just okay' or under-committing to one that's genuinely strong. There's a 'feel' aspect people talk about, but how do you actually develop that intuition without blowing up an account trying? Do you adjust based on a confidence score you assign, or is it purely mechanical until you've got thousands of trades under your belt?