There are many expressions commonly used in English to express similarity.
There is no magic rule to help you remember them. You just have to learn them. Sorry!
Take a look at the examples below.
To have eyes like a hawk.
If someone has eyes like a hawk, they are very observant and don’t miss things going on around them.
E.g. Don’t remove anything from her office without asking first. She has eyes like a hawk and will notice straight away if you do.
To be packed in like sardines.
This is used to describe a situation where it is very overcrowded or full.
E.g. I don’t like travelling on the tram at peak times. It’s always so overcrowded and the people are packed in like sardines. Sometimes you can hardly breathe!
Have fun learning English!
Louise