Dialogue can either be completely overlooked or overused by writers and it can be difficult to judge whether you're using effective dialogue.

Whenever writing dialogue, I'm constantly asking myself whether the dialogue is necessary to the text; if you use dialogue too much you'll find that your chapters will just seem like long conversations between two characters rather than a descriptive, engaging piece of writing.

However if you use too little dialogue, you may bore readers because your chapters will just be solid description which can be slightly tedious to read. Dialogue can break up description, however it shouldn't replace all description in the chapter.

I always think that dialogue like:

"Hey."

"Hey, how are you?"

is pointless because it's not exciting or riveting in any way. It doesn't add anything to the plot, and won't interest the reader. Dialogue should be primarily used to convey information or to move along the plot, not for mundane conversations.

Also, while on the topic of dialogue, don't be afraid to use the word 'said'. You don't need to use a synonym for the word all the time, however don't use the word 'said' for all dialogue as that can make your writing sound slightly flat and two dimensional.