From my point of view De Certeau's works have a phenomenological approach, but I find quite interesting his contribution to tactics and strategies as subversion forms to hegemony.
why do you want to employ De Certeau to study practices when there are theories of practices? I understand the incentive to find a way to grasp counter hegemony and I agree that theories of practices (Giddens, Boudieu, and partially Schatzki) often fail to see this.
My suggestion would be to look at the pragmatist notion of praxis which is definitely more than practices. It draws on both, the establishing of conventionalised practices and the way they are permanently contested in every day praxis. We tried to work this out in: The cultural sense of disasters (see link)
Regards
Klaus
Chapter The cultural sense of disasters: Practices and singularities...
I think Antonio Negri has given a really interesting contribution in this attempt.
Book
The multitude and the metropolis (2002)
Article
Urban social movement in Souther European cities (2006)
Whether you are interested in practicies of hegemony subversion I suggest to you one of my writings focused on housing struggle and urban social movements.