Probably viewing some kind of "video" or be VERY creative with ur imagination like ido where u imagine ur doing something very nice with ur Best friend or some other person lol and touch urself while picturing the idea

Masturbating feels good but it never got me all the way there either. Vibrators are good but for me it never pushes me over the edge. Being with someone is the only thing that has worked for me, if you and your friend are comfortable and close enough, when ever you guys have a make out session and things start getting hotter ask them to finger you. In my opinion you'd still be a virgin if someone fingered you or goes down on you but you'd get a real all the way there orgasm.