Since I have fewer callers nowadays, I am always experimenting to achieve more efficient way of calling CQ. Of course, I also watch the bands carefully as well. Hearing nothing, I start to throw fishhook with a bait. Various kind of baits are available. In my experience, each bait has more efficiency in this order.
1)Hand key nearly equal to bug key or side swiper
2)Electronic keyer manually sent
3)Electronic keyer automatically sent, that is, memory keyer
It seems our ears love something fluctuating. It might be related with the variable heart beat. Some people may say it is a memory in uterus of the maternal heart beat.
I know 1) is most efficient as a bait. But it makes me tired and bored. I often compromise with 2) category. i put an accent before giving my call. That is putting a small pause before my call. It may give an alert to listener that something important will be sent.
I must admit I sometimes surf the internet while sending CQ, because I have too few callers on the band. In category 2), I am apt to repeat CQ for many times without being conscious of that. Even worse, I forget calling CQ with category 3) and realize that transmission has been on due to the quietness. I should apologize to the callers in such occasion if any.
Anyway, I have scarcely considered of the efficiency of the bait some years ago. From now on, however, I need to make tricks to augment the efficiency of each bait. As if fishing on a lake where very few fish is in.