whether there are there any other good phrases to use
Here are some of the classics:
- 那个
- 就是
- 然后
- 嗯
These don’t really mean anything other than “well, uhm…” filler noises that could make you sound more fluent.
Chinese, of course, has hundreds other filler words and phrases, some of them are more or less formal. I actually have a special secret spreadsheet for filler words. For example here are some of my favorites:
- 总体来说呢 or 一般来说=generally speaking
- 关键是=the key is/the important part is
- 但另外一个方面=on the other hand
- 毫无疑问=without a doubt
- 据了解=it is understood
- 对我的了解=according to my understanding
- 我们换一个角度看待这个问题=Let’s look at this from another angle.
If you can train your muscle memory to say any of these effortlessly that should give you enough time to think what you want to say next 