Establish the type of show that you want to see. Las Vegas has thousands of shows that range from theater to ventriloquists.
Try to purchase tickets far in advance for shows that allow you to do so. For shows such as Marc Savard's "Mesmerized" at the V Theater at the Planet Hollywood hotel, you can book tickets in advance.
Consider shows that release tickets on the day of the opening of the show. The tickets are usually sold at half-price. Check out Tix 4 Tonight (See Resources below.) for half-priced tickets. Tx 4 Tonight also has five locations on the strip where you can buy tickets. They include the fashion mall in front of Neimans Marcus, the Hawaiian Market Place near the Polo Towers, the Showcase mall, the Four Queens mall and the North Strip by the Peppermill
Compare prices of shows at reputable ticket brokers such as Las Vegas Tickets (see Resources below.). They allow you to search for tickets from acts such as the Blue Man Group and Cirque du Soleil. You can search different dates, seats and pricing to find the one that meets your needs.