Bland in nearly every case means not enough salt. But the opposite or too much salt is worse, since it is usually easier to adjust for bland than salty. One of the greatest cooking skills you should work on is adjusting your seasoning depending on your tastes. You should get used to tasting your food throughout the cook time, and then add (normally) salt and pepper incrementally as required. Also get a general idea of how much salt you need to season a dish. For example, when I make soup it usually ends up being 2 1/2 to 3 quarts total - 1 1/2 to 2 teaspoons of salt is usually enough to season that to my taste, although I often add other salty seasonings like instant broth or Worcestershire sauce, which you should also take into consideration.
Another key technique in adding at the least a greater depth of flavor is carmelization, or developing what is known as a "fond." This normally involves sauteeing onions and garlic or other vegetables, or browning meat, and then incorporating the remaining brown bits on the bottom of the pan into a sauce for the dish or the dish itself, such as a soup or curry. If you brown meat, also be sure to add any juices back into the dish that accumulate if you place them into a plate while sauteeing your vegetables as well. After sauteeing/browning, be sure to use a liquid like wine or only water in the pan and then scrape the bottom with your utensil and try to dissolve the fond into the liquid.