On level 106 you should focus on making matches in the left side of the field. However, as the number of moves is very limited, you should use any chance you get to make power-ups. Do not rush into using the bombs though, including the firecrackers – try to get a couple of power-ups close to each other and activate them in a single move. This will clear more space and will charge the Lightning power-up faster.
Also, check if you can get to the crate in the top part of the field. There is a pre-set dynamite under it which can greatly help you in collecting the gold nuggets next to the granite. And bear in mind that you don’t need to remove all the earth tiles on this level – focus on getting just the ones with gold nuggets.