side reins when lungeing - which styles and why?

I’m curious: what types of side reins do you use when lungeing your horse? Vienna reins (aka triangle), side reins with elastic or donut, side reins with no elastic/rubber, no side reins. More importantly - WHY do you use them - what effect are you hoping to have, or what are you trying to correct or establish? When would you chose one style over another, or do most people choose one favorite and use that style exclusively?

I use draw reins set low-midway on the surcingle/on saddle billets, running through the bit, and attach between the horse’s legs (I guess like Vienna reins? I don’t really know as I’ve never used them). I love these as it really encourages a stretchy, back-up posture. They seem to seek and maintain contact consistently, and I love warming up like this for more rowdy horses (after a few minutes lunging without). Way better than regular side reins which I’ve never really seen encourage a horse to seek/maintain contact in (they always seem to back off from the contact a bit). I also like that it’s a multi-use tool and one less gadget I need to have (though I’m thinking of getting some regular side reins to encourage straightness during work in hand).

I rarely lunge without anything. If I can not ride its pretty quick to put on boots, surcingle and Vienna reins to give them a workout. I use Vienna reins with a surcingle. I always warm up and cool down with the long and low (between the legs to the bit and halfway up on the sides). Sometimes I will do our whole lunge session this way. This helps with stretching and helps build a good topline. The horse must be moving forward, tracking up and engaged from the hind end and not be lazy or behind. Both directions like this, even amount of time or slightly more one side if they are stiffer one way vs the other. Sometime I will raise them, Keeping one end half way up the side like before, through the bit and attach closer to the top of the surcingle (not very top). Again you have to make sure they are moving forward, not behind the bit and engaged. If they are not engaged, moving forward or behind the bit it is pointless. You may also have to shorten or loosen them depending on the situation. Can take some adjusting to get just right. I also have done cavalettis with these on as well, great for a horse who is being introduced to them as they figure it out on their own and work on their balance.