1/2" T45 tubing from ProFormance. That's what I use - see wishbone in photo above ^^^^. Not expensive, easy(ish) to bend, and generally easy to work with.
P.S. I'm about to order a new stash so if you want some, let me know. I usually order 1m lengths to have some wiggle room.
I've been using a £20 tube bender I bought off eBay. It's not ideal - the curve isn't entirely symmetrical and it does tend to put dimples in the tubing - but it's good enough for now.
1/2" T45 tubing from ProFormance. That's what I use - see wishbone in photo above ^^^^. Not expensive, easy(ish) to bend, and generally easy to work with.
P.S. I'm about to order a new stash so if you want some, let me know. I usually order 1m lengths to have some wiggle room.