Scaling out of positions: best practice?

Been trading $BTCUSD for a few months now, mostly small positions. I've got a decent grasp on entry points and initial stops, but I'm finding it hard to scale out effectively. Often, I take profit too early and then watch it run, or I hold too long and give back most of my gains. Are most of you using a fixed scaling plan (e.g., 50% at R1, rest at R2), or is it more dynamic based on price action and order flow? Curious how more experienced folks manage this without overthinking every tick.