One of Karen Walker's bridge themes is to advise "Think about partner's potential problems". In other words, what do partner's bids mean? Especially when faced with an unusual bid, pause a moment to think about what could have prompted partner to bid that way. Playing online, we made bad decisions on two deals that illustrate her point.
Partner bids spades, and when you raise to 2S, he bids 3NT. What do you do?
A few hands later, you bid 1S, partner bids 2C (you play 2/1, so this is forcing to game). You bid 2NT and partner raises to 5C. What do you bid?
Your two aces are golden. One is in partner's suit and the other will win the first trick. Bid 6C. On this hand, 7C and 6NT easily make. In clubs, you can establish the spades and throw your diamond loser on the good spade. Dummy's clubs give you two entries even if they lead a diamond on the get go. 7NT also makes because East gets squeezed between hearts and diamonds, but I don't know if I will be alert enough to follow East's diamond discards. to know that my 8 is good.