If your company does LOFT sessions in the sim recurrent, ask to be the "lead" in those. Practice your company's preferred method of dealing with non-normals and emergencies. (Emergencies are relatively easy, follow checklist, land somewhere suitable). Practice decision making. Easier said than done. Eg, we use RSIC-t-DORDAR. Whatever system is used, get familiar and comfortable with it. If a captain makes a decision and you can't follow how s/he got there, ask when you can.