The AA.

I have jumper leads but they've been lent to somebody, so technically I don't any more.

As a mechanic I always try to carry what I need to be able to help myself. With a set of jump leads, on the odd times I've ended up with a flat battery I can always find a helpful soul to loan me their battery for a jumpstart.

Although if I'm desperate I can always try to jumpstart it.

My 'reached that stage in my life' Yaris would not start on one of the cold days just gone.

Had to get the AA man out and of course he sold me a new battery.

This thing packs a bigger punch than my Yaris while running! 

Have had a flat battery a few times already, thanks to a system that is supposed to only keep the Blackvue Dashcam running for a while after parking the car. Unfortunatly it kept the camera running until it depleted the battery.

Both times I was helped by my local Toyota dealer (thanks Toyota Hawkes Bay!) for less than it would cost to have AA come and rescue me.

Have stopped using the system to keep the Dashcam running, and also ended up buying a new battery (the old one was 5 years old). 

I have jumper leads so wuold find a frriendly sole to assist. I'm also a Coastguard volunteer so could be great on the boats... It's hard to push start a boat ;-).

I would phone a friend like last time it happened when I was leaving from work.

My current flat battery strategy is to call the AA if it's urgent, or if not I've got a 12V trickle charger which takes overnight to get her back up.

I'd keep this in my boat most of the time i think. Useful for charging devices while in the middle of nowhere catching fish. 

On the other hand - I'd also make good use of it charging items at home - then dragging the power cell to work to re-fill it. Saves on household power bills :-)

Most likely call a friend, otherwise use AA if travelling