1.你好（您好），请问，你的电话是多少？ 2.你好（您好），能告诉我你（if you're gonna talk to your boss,you'd better use"您"）的电话是多少吗？ "打扰了"，"你好"and"您好",those are options. Have a nice day:)

您好，请问方便留个电话号码吗？ politely in Chinese is 礼貌地or有礼地

你好，如果方便的话，可以给我你的电话号码吗？

I can tell you a simple way: before the question, add "请问" replace 你 by 您 for example, question: 你的电话号码是多少？ polite question: 请问，您的电话号码是多少？

You may notice that chinese seems so abrupt. It's much more direct than our culture, we always use extra words to show politeness, we use it too much. "Can I please have your phone number?", "Could I have?" etc... I always thought it was impolite at first when seeing chinese people just ask things, for example to waiters: "bring me this." not "can i please have ..". I find the chinese way better - politeness has a lot more meaning when it's not a social requirement to say it in every situation without fear of looking impolite.