Attractive opening leads against a suit contract are "top-of-a-sequence-of two-touching-high-cards". Especially an Ace from AK, Singletons (not trumps), and partner's suit. However, if you have none of the above, then we should try and do the following:
1. Listen to the bidding which is a great guide of the opponents shape. The higher they bid, the more you will know about their hand pattern.
2. Do not lead away from an Ace.
3. Do not lead a singleton trump.
4.Do not lead doubletons unless partner bid the suit or they bid 3 suits and it is the unbid suit.
5. Do not lead a low card from four cards to a 10 or lower. It shows an honor. Lead second highest to show no interest and no honor.