thatdonald845 wrote:
Has anybody been able to work out if it is better to leave firing your cannon until near the very end of its cooldown period - thus leaving the floating icon there for visiting neighbours to tap - and for you to wait and collect on?
Or even only firing two shots so that the icon is still there?
No, don't do that. Neighbours can tap your cannon regardless of whether it is in cooldown or not -- the only limit is that they can't tap it if it already has a handshake. So your goal is to clear the handshake as fast as possible regardless of when it appears. (This is where the "X has visited your Springfield" push notifications are actually useful.)
Personally, I've never had a problem keeping a surplus of elves -- it's been slowly growing in fact, and I'm now at ~250 extra. I'm probably not firing the cannon as often as I could, but I'm still maintaining a bell income ahead of the daily chart. So unless you're desperate to get to the free donuts at the end (assuming they do that again) I wouldn't worry about it too much unless you're behind the chart.