Putting her on the tree is fine, just try to do it when you are in the same room with her so that she can see and hear you. It provides for her sense of security and well being because she knows that she is not alone.
It can be tricky at times because she also needs to learn that you can't always be right there with her and when that is the case that you will return so everything is alright. When this happens she will likely scream for you so it is advisable to start slow and tell her bye-bye, I will be back ( or something of the sort ) then leave for 5 or 10 minutes and when you return make a little fuss telling her I'm home ( or similar ) gradually extending the time til you reach the normal time you would be absent. Please don't try to trick her by staying and pretending to be gone because she will know the truth.
The same holds true for time on her perch or tree, while she needs to be out a lot she also needs to allow you to go to other rooms or outside and you accomplish this in the same manner starting with a short time, letting her know you will be back soon and do your thing and greet her when you return, pet het so she feels secure that you are not abandoning her. During these times you can talk to her from wherever you are ( she knows you are there anyway ) and she will call and whistle to you in return maybe even talk to you. Treat it like a game especially made for her.
There is no single best way to do anything so feel to alter this or do it however it works best for you. Let us know how it goes.





