The fastest way is to take flight from Guangzhou to Macau while the cheapest way is to take bus from Guangzhou to Gongbei Bus Station and then go through Gongbei Border, you will get into Macau. Well, the best way for you is to take the cross-border coach from Guangzhou to Macau, you can find the coach in front of many big hotels in Guangzhou such as Landmark Hotel Guangzhou.