the normal jewellers method is to wind a coil around a suitable mandril ( slightly smaller diameter than required ID ) then use a saw ( not cutters) to cut the resulting coil into rings. Solder the ends together. It takes longer to explain than to do. If you use cutters to " snip" the coil you need to file the cut ends flat.
"that's not a bug its just an undocumented creature."
Sir Terence David John "Terry" Pratchett, OBE (28 April 1948 - 12 March 2015)
I would confirm you need to heat the brass to cherry red to make it soft enough to take the springiness out of it, then wind it round a mandrel a little smaller and saw (piercing saw) into rings that you can solder as he says. But 1.8mm brass will need softening first.
Annealing brass agreed you need to anneal brass if you are bending it, this is easily done by first cleaning it and then heating to very dull plumb color (600 degrees) and then quickly quench in water, don't forget that brass work hardens so if you are making complicated shapes its a good idea to anneal part way through the bending or repeated hammering process.