Things that are good to know if you are going to take care of corvids:
Crows have neophobia. This means they are afraid of anything they have not already seen. Crows and magpies can start repeating their distress call by screaming really loud!
The other birds in the crow familly are usually not as loud but they will be afraid.
You can quite often see that because they open their beaks then.
Crows do not like checkered clothes and crows tend to hate black objects more than others. I do not know the psychology behind this, but try to avoid this please. It is generally best to always wear the same clothes so that the birds stay calmer. A green uniform can be bought quite cheaply (Check out the links on this website)
When you put corvids together, there can be trouble. If there is plenty of space, they should be able to flee (within the confided space of course). It is important that they have room for that. NEVER put a raven together with any other crow bird. Then they will try to kill each other. There are known exceptions, but please don´t try.
Also, magpies are hard to pair with other species. Sometimes it works. It is possible to see how it goes but then you really should put several days in constant surveillance. You do not want to take the risk to damage one of them.