What are some of the best ways to close a sale?

Probably need to be more specific with your question in order for any answers to be helpful. What type of product do you sell and who do you sell it to? When you say close a sale, do you mean improve the deal close rate? At which stage does your deal get stuck?

Since this question is too broad, I will just recommend some books to help you out no matter the context. Give “The Challenger Sale” a read, and if you are forming your sales process from 0 give “Sell more, Faster” by Amos a read.