吃完饭后，你可以使用以下几种英文表达方式：

简单句

I have eaten.

I have finished eating.

并列句

I ate dinner. Then I watched TV.

We finished our meal and then went for a walk.

复合句

After I ate dinner, I felt full.

Since we had finished dinner, we decided to play games.

描述性句子

The meal was delicious, and I ate every bit.

After dinner, I like to relax and read a book.

对话形式

A: Have you eaten yet？

B: Yes, I have. I just finished.

根据你的写作需求，可以选择适合的句子结构和表达方式来描述吃完饭后的情景。希望这些例子对你有所帮助!