What kind of cuttings: I like 2nd cut which is what most people use for their rabbits. 1st cut is mostly going to be seed heads, which is good when your rabbit has stasis because it is full of fiber. 2nd cut has some seed heads, but mostly has long strands of strong hay, with some softer hay. 3rd cut is soft hay, it is normally short flat pieces of flaky hay which is not ideal for rabbits. It won't wear down their teeth that well because it is so soft.
Preference for "brands" that seem to have good hay: I agree with
@HJ :), find a local farm. If you can't find a farm you can get Small Pet Select hay but I still think it is super expensive. I get a bale of compressed Timothy hay from Tractor Supply. I have gotten 2 bad bales in the past, so now I check the hay before I buy it. If it has a bad smell or looks flaky I will get a different bale.
What look is ideal: Long hard strands with some seed heads.
How can you tell if hay is bad: It is very obvious when hay is bad. It will be musty, dusty, and dirty. When you grab it, it will get dirt all over your hands
What does bad hay smell like: It really just depends, but you will be able to tell! Fresh hay smells like freshly mowed grass. When I had a bad bale it smelled like moldy essential oils.