Recently I took a class on moxibustion and now I want to buy some moxa sticks. How do smokeless moxa sticks compare to others? What else should I loook for when choosing moxa sticks?
Moxabustion is moxabustion in part because of the smoke which transfers the properties of the herb via heat and oil to your body. In my opinion smokeless moxa sticks are only to be used in places where you cannot use regular moxabustion sticks. As far as which ones to buy it probably doesn't matter. If you are doing okyu (thread moxa) or other techniques from a Japanese perspective you generally use higher grade moxa.
I want to know clearly about the effect of acupuncture alone and combined with moxabustion
That's not really a valid question. Moxa is generally considered warming, moving and tonifying. Used on the wrong points in someone with a heat condition you could make them much worse for example. For moving and tonification it can be very helpful. I suggest you read my article - What is Moxibustion?
In short, for some conditions you would never use moxa and for others it could make a difference clinically although for moving other techniques such as tuina can be used with or instead of moxa and tonifying can be done with herbal medicine and used in conjunction with or in the absence of moxibustion.