Crouton seasoning

I have been making homemade croutons with gluten-free breads that are also homemade. This is a result of my wife who has been diagnosed Celiac.

Anyway, I am asking for input on seasoning for the croutons. Typically, I use onion powder, seasoning salt, oregano, and often italian seasoning or basil to season the croutons, using a base of butter and EVOO (close to equal, but sometimes more butter). They are turning out rather bland and non-flavorful overall.

What advice do people have for making exciting and flavorful croutons, and what advice can you give me for making better flavored croutons?

Thanks in advance,

bon appetit