1. 在动词后面使用搭配 “my own (我自己的)”，可以表达 “我为自己或对自己做某事”。这里的 “my” 可以用其它形容词性物主代词代替，如 “your”、“her”、“his”、“their”、“our” 等。

Can you make your own decision, please?

The little girl is doing her own laundry! 

He makes his own dinner every day.

2. “On my own” 的作用类似于副词 “alone”，用来表示 “我独自地”。这里的 “my” 也可以用其它形容词性物主代词代替。

I think she likes spending time on her own.

He lives on his own.

We were on our own when the doorbell rang.

3. 我们可以用 “by myself” 来表达和 “on my own” 一样的含义。这里的 “myself” 可以用其它反身代词代替，如 “yourself”、“herself”、“himself”、“themselves”、“ourselves” 等。

I think she likes spending time by herself.

He lives by himself.

The kids went to school by themselves.