Long reins - length?

[Kub]

Looking to get some so I can get coblet long reining, my lunge lines are just too long, end up with sooooo much extra line lol. So what's the ideal length? And best place to 'em? Ta

 

[Miss-rose]

Not sure what length you will need but a few yrs ago I went to my local diy shop and bought a really long piece of thinish nylon rope took it home measured how long i'd need cut to length then added some clips at one end and tied loops at the other end. The result was a great pair or reins that are neither too long or short, cost next to nothing and there still going strong, hope this helps