Is anyone using any formal risk assessment methods prior to every flight? Meaning things like risk assessment matrices, quantitative risk assessment flow charts, PAVE, etc?
There are many models that are useful in flying that we don't necessarily apply explicitly on every flight. For example, when I understood the relationship between pitch, power, configuration and performance, my instrument flying got much better. But I don't do detailed calculations of power and pitch required every time I fly an ILS -- I use rules of thumb and experience that are consistent with the model.
I think you should use these risk assessment models in a similar way. There are principles that can be introduced to your mental models without running through explicit process models. The quotation from the introduction of the FAA handbook is a good start:
“A key element of risk decision-making is determining if the risk is justified.”
Risk is an inevitable aspect of flying, but it's important that judgements about risk are made rationally, not from ignorance of the risk factors, so that we recognise when the risk starts to become unacceptable. The tools are designed to raise awareness of hazards and to support the rational analysis of whether the associated risk is acceptable.