Hello:
I am in a similar situation. Over the last few years I have lost my sense of tasted smell. This can be challenging because mostly what I get is sweet, sour, bitter, spicy - with very little taste. All I really have is my memory of what the food tastes like so I try to concentrate on that.
My wife will ask me how it tastes - my standard answer these days is "nothing objectionable".
I like your ideas about adding more spices.
Sometimes the thought of food turns me off. Having to deal with no test and weird textures of food can be a bit overwhelming - if that makes sense.

When I was in the Navy, we would go to chow and there was always a group of bottles on the table. We called that bottled flavor!!!

I hve wondered if others having problems eating or appetite - if they have issues with taste and smell.
It can definitely affect your appetite and lend to being picky about which foods are good - today (same stuff might be a turnoff tomorrow). Some of us have a harder time communicating this. If your loved one isn't eating much - maybe this is a contributing factor?

Peace
Larry H