Varrock border rats 1-40
Northeast of edge thugs 40-99
Lvl 27 west wildy 60-99
Edgeville dungeon is great for going from 40-99 with a couple different lvl mobs  and it's a short walk from bank
http://postimg.org/image/v4fiylf3p/
^ map of rscr wildy will give u a better idea of where certain mobs/lvl are

around 75hp go to a higher lvl wild spot, pirates is fastest and just stay there afk, keep logged in as much as possible till flats.

Yes for higher xp, but higher chance of getting killed too.

I find the best spot due to its quickness is the thugs near edge, if you die, port back and 20 seconds later back at npcs.

ANother good spot is the dark wizards over in west wild, not as many pkers go there since its a bit further of a walk, but lvl 13s and 25s to kill for good xp.  Higher def characters dont get hit much at all from them either so can easily 3 item it (or 2 with sleeping bag).