If you are on a tight budget, there is a public ferry from Padang Bai in Bali to the port of Lembar, 22km south of Mataram on Lombok. The crossing takes 4 to 5 hours, and ferries leave about every 90 minutes, 24 hours a day.
From Lembar, take local transport or a private car to Bangsal Harbour, then a boat to Gili Meno.