I didn't actually. I was in a section with Eligos, when I got interrupted by Abaddon and he started talking to me and when i asked if he was my guardian he replied more than twice yes and I saw him a bit in my dreams that night also.
To call upon any demon follow the ritual on JoS, it works perfectly if you open your mind enough and get in trance. The first times you will not notice signs right away but with time you will get to feel presences around you.
Regarding Abaddon, as I said earlier I wasn't trying to contact him at all but I guess it was time for him to let me know that he was my guardian. I don't know any other ways beside that. Oh and I should mention I was using an Ouija Board that I made specifically towards what felt the better way to communicate with the gods (combined a bunch of symbols).
But i would suggest if you are new to communicating with powerful gods in general, create or integrate to your own altar representations of North,south,east,west, with the representations of each god of each corner. I would suggest using natural items like stones or a bit of dirt, water etc if you can't do the rituals outside. TO me personally it helps connecting more with them as I do always call upon Lucifer Beelzebub Astarte and Azazel everytime i tried to contact demons because it makes me more opened spiritually. But this is personal though, it might it might not work for everyone.
Hail father!