WE used to always cut them with a torch, I have even cut and rewelded them back together,
If you do that, they aren't springs any more. Heat kills the temper.

When I used to cut springs, I'd figure out what I thought I needed, then take half or less. It's a lot of work taking them in and out, but it beats buying a new set of springs. Also keeps you from having to say "Gee, I cut it off twice, and it's still too short."