Normally, I use mushroom powder, but now it is out of stock in my place (New Zealand). The alternative to me is MSG or other artificial seasoning powder but I know they are not good for my health. Is there any way to sort the problem regarding seasoning powder out?
I am not sure if I'm allowed to mention any brands here, but I really like Deliciou.
It is Australian brand and they ship worldwide, so I guess it would be easy for you to order. They are 100% vegan and the ingredients seem to be good as well.
In general, you can make your own spices by mixing basic ingredients. There are many recipes on internet or in any proper vegan cookbooks. Your question is very generic, so I would say just find the mix that works for you.