1♣-1♥ 1NT-2♠ Spades must be longer than hearts- if you play some form of checkback, you'd use it with only 4 spades, if you don't, partner would never bypass spades to bid NT. That's really only to show 5-4, not 6-4, so maybe it is better to start with spades and then bid hearts with this. longer suit first, that's most players play. The more you bid second suit, the longer the first (and the second) suit is. As Chuck said, 1H and then 2S/3S, shows 6H-5S, or could be 6-4 in some occasions.