Leave team training to assistant.
Pre-match team talk: use whatever the assistant suggests.
In-match: substitute anyone with 6.4 rating or less. Substitute anyone with a yellow card. If 2 goals have been scored, substitute the GK. You can try using shouts, I never do, so I don't know if they'll help or hurt.
Half team talk: if losing, ignore assistant and say you're disappointed, calmly. If you're winning, use whatever assistant recommends.
If you win, give players 1 day of rest.