Well, number one thing obviously is make sure you are at a quiet place with good phone connection at the schedule time. It sounds silly, but it can be an issue.
Then study your resume and the job description, be prepared to talk about how you qualify for the position based on your resume, and have an answer for any glaring deficiency like gaps in experience or no experience in certain preferred technology.
Some interviewers will ask coding problems over the phone, but it is most like something generic and answerable within 5 to 10 minutes and nothing you cannot answer with pseudo code. Reverse string, find palindrome, depth first search, things of that nature. No need to over study for it, just know that it’s a possibility and it won’t be super complicated.
Write a little cheat sheet on things that you think might trip you up during the interview, as well as have your resume and job descriptions handy, also have pen and paper ready to take note if needed. The cheat sheet is not there for you to read off, it should just be something of a security blanket, something you can glance down in a panic and right yourself.
Otherwise, practice your elevator pitch and do your best to sell your candidacy.