We usually like to make an attacking opening lead to set up tricks in your long suit. Lead the fourth highest ( count down from the top ) from your longest and strongest suit.
Avoid leading a short suit unless partner has bid the suit.
Avoid leading Aces "from spaces" or "unprotected high cards".
Avoid leading declarer's bid suit.
Remember :
1. Three cards touching or nearly touching each other are sequences against a No Trump contract. We lead the top.
2. Two cards touching each other in a No Trump contract , we lead 4th highest .