" nous avaient donné plein d'astuces et de conseils à suivre. "

Just to ask why it is "de conseils" , not "des conseils" ?

Is it because it is a continuation of "plein de" ?

I believe plein de is invariable, i.e. would never use des.

e.g. "plein de trucs" , "plein de choses"

Thanks

Paul.