First, Gatsby sends someone to mow Nick's lawn and work on the landscaping so that it looks better for when Daisy gets there. He also has dozens of fresh flowers sent to Nick's. In his own house next door, he turns all of the lights on so that Daisy will hopefully be impressed by it. Finally, he dresses 'comfortably', but in impressive clothes. He does all of this so that Daisy will be impressed by his wealth and hopefully fall in love with him again.
