My favorite shoujo manga magazine is Betsuma (Bessatsu Margaret). It currently has five manga that I’m following: Aoharaido, 360 Material, Heroine Shikkaku, Junjou Drop, and Kimi in Todoke.
My favorite josei manga magazine is PuchiComi (Petit Comic). Current manga that I’ve been following are: Hapi Mari, Yamada Komomo’s works, 2-Dome no Koi wo Usotsuki, and Yoshihara Yuki’s works.
I subscribed to Petit Comic for several months last year and bought two issues of Betsuma, but it just got too expensive… so sad. It would be great if there was an e-version of the magazines. A few magazines are starting to be offered electronically, but not those two… maybe someday.