Basics matter most. However, subtleties can add to the credibility and reinforce the unity and progress of a message. An intriguing title subtly stated at a key moment in the sermon. The opening phrase of the message repeated later, perhaps even twisted. Subtle humour when appropriate. These things are usually better subtle than blatant. If some people miss it, there is no harm because it is subsidiary to the important elements of the message – the big idea and purpose, etc. However, if some people catch the subtleties, then the message effect is reinforced.