20 defence?

I know Rock Crabs are decent but they're absolutely packed.

I have ~30 attack and strength; quested defence.

Monks are pretty good until you hit about 40 atk/str

Alright thanks, I'll check those out.

I know I did those when I made an obby mauler a very long time ago.

Try waterbirth rock crabs, there's a few 2 rock crab spawn locations on the island. AFKable and not as packed as some worlds at normal rock crab locations.

Another few places where training is fast/profitable would be:

 

Muggers (located in edgeville dungeon, level 1/2 wilderness) ; these drop herbs and clue scrolls.

Chaos druids (located same place as above) ; these drop herbs and average 200k a hour + good xp.

Experiements (require priest in peril quest completed, and frankinstein's quest started) Good xp, althoguh crowded.

Zombies/skeletons (many locations)

 

All monsters around your combat level will be good xp... just some require more clicking than others.

Really good advice. Thanks man.

Too bad half of those places are packed, but I never thought about muggers. 

I'll check those out in a bit.