Advice to those just starting out: rehearse

Epictetus, Enchiridion, Chapter 4:

Whenever planning an action, mentally rehearse what the plan entails... 'I want [to do x], but at the same time I want to keep my will aligned with nature.' Do it with every act. That way if something occurs to spoil your [plans], you will have ready the thought, 'Well this was not my only intention, I also meant to keep my will in line with nature - which is impossible if I go all to pieces whenever anything bad happens.'