If you want to stick with TOTW, I also am using it, I switched it from Blue Buffalo, because its grain free, a decent dog food brand, and a decent price.
You can add wet canned food, homemade chicken/rice, or you can buy some irresistible freeze dried liver treats and crumble them on the food.. It gets my pup to eat her food any time of the day! I finally figured out that trick.
Sometimes they get sick of the taste, so you might have to just switch different flavors/brands or just add a topping, my friend switches from Blue Buffalo, California Natural, TOTW, etc. after she is done with the bag, because her dog gets sick of the taste. My dog has a sensitive stomach, so i cannot do this with her.