I've found that there are a couple of times each sail that I need to keep the tiller still - singlehanding, dousing the jib, heaving-to, etc. - and each time I've used various combinations of bungee cords or lines, all feeling clumsy and hard to do quickly. Most fun is when the bungee flies off and hits spouse in face.
So I looked at some of the commercial products, but found them wanting for various reasons. I devised a simple and cheap solution that works. I put it through trial runs yesterday.
I tied a line between the two rear docking cleats, and looped it, under the tiller, through a strapeye. I put a small block on the loop, and tied a line to the block and pulled that through a clam cleat. A picture's worth a thousand words:
top of tiller
bottom of tiller
individual parts look like this
The clam cleat is about six inches from the end of the tiller, so the line is easy to grab about yank up into the cleat. There's a knot at the end of the line to prevent it from running out of the cleat.
All it takes is a good strong pull then cleat and the tiller is pretty stiffly set.
There are lots of ways to make something like this work - I'm sure I'll alter a few things. But it's very cheap - the parts were less than $10 total (probably less - rough estimate) and it was easy to install.