If you mean a medium clue scrolls then try killing Guards, Giant Rock Crabs, Men/Women (level-24), Tribesman, Cockatrice, Dagannoths, Harpie Bug Swarms and Rock Crabs.
if you are looking for a level 3 clue scroll which i recommended i would fight jelly they are the best for clue scrolls if you don't have the slayer level I recommended ranging hell hounds. You can get form 100k-114m off of Level 3 clue scrolls. You can get 400 million if you get really lucky with the third age armor.
I guess you could do bandits!:D
The best and most efficient way to train defense on runescape member's worlds is to train on rock crabs. Rock crabs have 500HP, low defense, and a maximum hit of 15, they also drop clue scrolls.
I have gotten level 2 clue scrolls from the guards in Burthorpe and from cockatrice in the slayer cave of Relleka. you have the best chance of getting level 2 scrolls form guards if your a low level. I recomend going to falador
The best spot to train hunter in is the Feldip Hills as it can support your hunting to level 45.
The best place to get crimson Charms would be killing the high level cockroaches at the player safety dungeon.
a nobermom
The Wilderness.
GameStop has it for about $10.
The best way to get lvl 1 clue scrolls is to kill lvl2 men or women or kill goblins lvl2.
It really depends: on your slayer level; on your combat level; and on your preferences. Some of the masters will give you easier slaying tasks, some will give you more difficult slaying tasks. Once you have the appropriate level, a higher-level monster is more likely to give you the higher-level clue scrolls (if you are interested in those).
the best level is about 139 now