Scaling up CFD position sizes with risk management

Been trading CFDs for a few months now, mostly on forex pairs like $EURUSD and $GBPUSD. I'm profitable, but my position sizes are still pretty small – just enough to feel the market without risking too much. I'm trying to figure out how to scale up properly. I hear a lot about 1% or 2% risk per trade, but how do you guys actually apply that when moving from, say, 0.1 lots to 0.5 lots? Are you just increasing the capital in the account, or is there a more dynamic way to adjust based on volatility or recent performance? What's your process for increasing your stake without suddenly blowing up your account?