botch up

He botched up the presentation by forgetting the key points.

他因为忘记了关键要点而把演示搞砸了。

I've botched up the repair, so now the machine won't start at all.

我把修理搞砸了，现在机器完全启动不了。

She is botching up the cake by adding too much salt.

她加了太多盐，正在把蛋糕搞糟。