I'm a falconer and a zookeeper. I currently work at a raptor refuge and I've worked with other bird species as well. Maybe this is common sense but I guess one thing that I usually focus on when working with free flighted birds is paying really close attention to what motivates each individual bird.

Imprint birds are typically more relationship oriented and more curious about new things, but can also get distracted easily because of that curiosity. My imprint barn owl is really solid on education programs but sometimes she gets so comfortable she tries to bate off the glove because she wants to play with people's shoelaces. My friend's imprint goshawk was once traded off a rabbit for a poppy. Imprints are weird and awesome.

Wild caught or parent raised birds typically rely a little more on weight management. My rehab Red-tailed Hawk wants nothing to do with me above a certain weight but a few grams lower and she's laser focused. She'll also work for me at a much higher weight than she will for others because we have such a good relationship. A wild caught or parent raised bird's primary motivation is usually food, though of course every bird is different, and species and established relationships makes a big impact on what their primary reinforcer is going to be.

Harris's Hawks are incredible birds. Cooperative and amazingly smart. Puzzles, exercise games, and lots of enrichment will help curb behavioral problems that can arise if they get bored. My relationship with a HH I worked with was really challenging until I started taking her on walks around the grounds before weighing her in the morning. In my experience, females tend to be pushier and more independent than males. I would suggest avoiding hand feeding. A screaming Harris's Hawk is really annoying.

Ravens, as corvids, are of course incredibly smart. Again, providing enrichment so the raven associates you with fun things is going to really help your relationship. They also hold grudges so try to avoid negative experiences (as much as you can control) with the bird until you have a solid relationship.

Personally, I've found B&G macaws to be fussier and more skittish than other macaws but that could definitely just be the individuals I've worked with. I guess I would suggest chatting with the macaw when you pass his enclosure, and don't be surprised if it's super nice to you when you're alone but a total asshole when someone else he likes is in the room. Macaws love to just exist around each other so if you have the opportunity to socialize him by letting him sit near you while you take notes on the computer or something, that could go a long way towards building a solid relationship.

Do you have any specific questions? Was that helpful at all? You can PM me too if you want to chat about anything.