Using a subject:
* The cat sat on the mat.
* My friend loves to bake.
* This amazing view makes me feel happy.
Using an adverb:
* Slowly, the train pulled into the station.
* Sadly, the show had to be cancelled.
* Fortunately, the rain stopped just in time.
Using a prepositional phrase:
* On the beach, we built sandcastles.
* In the garden, the flowers bloomed.
* After dinner, we went for a walk.
Using a conjunction:
* Because it was raining, we stayed inside.
* Although I was tired, I finished my work.
* While I was cooking, the phone rang.
Using an adjective:
* Green leaves rustled in the wind.
* Happy children laughed in the playground.
* Delicious food filled the air.
Using a verb:
* Sing!
* Run!
* Think!
The best way to start a sentence depends on the context and the message you want to convey.