Yeah, basically what leggy said, I wing it and I usually like the game I buy.

It really depends on when my next chance to buy it will be. If it is a one shot deal, I try to use the packaging for clues. For instance, if I know the developer, year, genre, and a few other minor facts within the diction of certain phrases, I can make a fair guess usually. I watch review shows like Classic Game Room and the Angry Video Game Nerd (Or Angry Nintendo Nerd) and if I see a game that they covered, I will have a clearer idea what I'm getting myself into. For instance, when I was looking for some games for my NES recently, I was able to save myself a lot of pain because several games there I knew for a fact were sub-par to be generous. 

Truth be told, the only time I seriously got burned on a game was Heroes of Might and Magic 5...oh yeah. I loved the earlier games in the series, and came across this game...oh boy...I think I paid around 40 or 50 dollars for it...

Anything well publicised like anything by Pokémon, any final fantasy and any Zelda's and always looks at the back of the box's you buy and see if the games for you so like look at what type of game it is like platform rpg , etc... look at some of the in game pictures see if it looks like something you might like apart form that I guess theres not much else you can do unless you specifically look for a game before going to the store on game review websites which is a good idea I guess don't want to waste your money

I don't, to be honest. I just look at the trailer, wait fir box art, and if they're both good, I'll buy it. Funny thing is, I havent been unsatisfied with my process yet.

                    The way that I make sure I am buying a good game is I search it on you tube and see it's game play.I want all my games to be good   none of them will be dull.So far all of my games for ps3 are the best of their kind.Another way I would make sure that a game is good is by reading a gamer magazine.Every single game that I have bought has been very popular.