Choose any two of these short simple sentences. Firstly try joining two with a connective to make them into a longer sentence (it can be silly).
Then look at verbs can you keep meaning but make them more powerful?
Now are there adverbs you could add to describe these verbs?
Could you add in any adjectives?
If you've run out of ideas use one of these as a starter then add a connective then your own ending before doing the above.
The cat sat on the mat.
The grass was wet.
The rain didn't stop.
The boy knocked over the drink.
The dog ran down the road.
The mouse hid in the cup.
The cat went to the shop.
The girl walked across the grass.
The sun came out.