I consider myself more of a buffet maven than miles maven. I think buffets are best for variety not quantity.
I don't like many Chinese dishes, so at buffets, I only get one-two types of chicken, broccoli, and rice. Not good value because I might overeat, so I prefer to just order a meal at a Chinese restaurant.
Indian food, on the other hand, I like almost every dish, so I get tremendous value from a varied Indian buffet.
Here are my tips for maxing out an Indian buffet specifically, but any buffet really:
1) Know how much food is too much and will make you feel bad. Go in deciding to have less than this amount. At my favorite Indian buffet they have regular size plates and tiny ones for the salad area. I've found that exactly one regular plate followed by one tiny plate of my favorite dishes is the optimal amount, and I enforce this rule on myself every time.
2) Go easy on the rice. How?
3) Layer your food instead of putting each into a section of the plate. I start with a one grain thick layer of rice. That way I can get it in every bite, but I eat very little of it. Then I put a quater to half inch layer of each veggie dish, then scoop the chicken on top. The mixing of flavors and portion control of this method is top notch.