Mrs. Cuillo
Sous Chef
If it tastes bland to you, add more salt. Do it slowly, tasting after each addition because while you can always add more, you cannot take away. I use a bit of sour cream in my mashed potatoes, too...it rounds out the flavour. You could also do roasted garlic, or pesto, or sundried tomatoes.
A coworker brought in some mashed potatoes that she put cream cheese & sour cream in with cheddar cheese on top. They were delish!!! You could also try mixing bacon in to add the saltiness you are looking for & some texture. Just experiment with different things...a little Mrs. Dash also could change it up as well!! Good luck!