It's partly about capacity. Someone's already given you the best advice there is, and that's 'be prepared'. You can maximise yours by ensuring that you know your checks, emergencies, flying orders, SIDs, approach procedures, frequencies better than anyone else. Sharpen up your mental arithmetic and nav calculations. Be as fit as you can be. Get enough sleep. Eat lots of vegetables. Anything that aids concentration and frees up brain space to deal with what they throw at you......