Ace, queen, knave, and small.
Lead ace.
With more than four in suit, lead knave after ace.
With only four in suit, lead queen after ace.
Ace, queen, ten, &c. (in trumps).
If knave is turned up to your right, lead queen.
Ace and small ones (in trumps).
Lead ace, if you have seven in suit, and then a small one (the original fourth-best if an American Leader).
Lead a small one (the fourth-best if an American Leader), with less than seven in suit.
Obvious variations, taking into account the trump card, are omitted. It is assumed, e.g., that, if your partner has turned up the king, you would lead a small one from ace, queen, knave, &c., or from ace and any number of small cards.