Fastest way to get up F2P magic?

I finally gave up on any chance of my RS macro appeal working after 2 years. Made an RS3 account and so far all I've done is train magic. I'm at level 16 right now. Actually, I'll probably be 17 by the time I'm done typing this. Whatever.

This new way of earning XP (actually having to kill the NPC) really pisses me the fuck off, and I swear I get less XP than I used to for the same amount of work. What's the fastest way to get my magic back up there?

I'd like to avoid subscribing until I get some of my F2P skills to a respectable level. Waste of membership to do otherwise.

 

http://runescape.wikia.com/wiki/Free-to-play_Magic_training