Using the Woolsey convention, the main overcalls after a 1NT opening are:
- 2 clubs (Landy convention) with the majors at least 5-4
- 2 diamonds a suit normally with 6 cards
- 2NT calling for the minors with preferably 6-5 (quite rare)
- 2 ♥ or 2♠ with a 5 card major and a minor 4th
- Double showing a long minor and a major of at least 4 cards
Don't forget to check who is vulnerable and that your distribution is more important than your HCP. Your honors should be concentrated in the suits signaled.