The best place to do it in my opinion after a personal test is at Hellgate. Not only that, this place gonna help you with Elder Bonelord and Demon Skeleton bestiaries, and probably also will help you with Skeleton, Ghoul and Slime. The place is easy to reach and is a Free Account location, so I would recommend to you pay a visit there, specially if you are a Free Account. As an even more special bonus, you can get a good profit there due to a relatively recent valuable loot dropped by these creatures!
A good level to be there would be 35 and having Stealth Rings, Great Fireball Runes and possibly the Invisible Spell. These creatures are easy to deal at long range but they can problematic if you are a Knight. As a knight I would say that level 35 is doable taking care of yourself and having a lot of health potion, but it would be much more doable and profitable as a level 45 and higher, preferably using a good two-handed weapon against the Bonelord race. However, test it by yourself. Arguably with Stealth Rings and really good skills you can manage to hunt in lower levels!
The profit will come specially from Small Flasks of Eyedrops due to the Bewitched event, so I really recommend to you give a try there if you want a good profit with this creature item!
I have made a video hunting there where I explain a few things about the location https://www.youtube.com/watch?v=glwOWDuIqRg&feature=youtu.be
You can reach there by using the following path:
The last image is the Bonelord Area in Hellgate!
Image describing route to Hellgate was obtained on: https://www.tibiaroyal.com/en/guide/quest/99/draconia-quest/spoiler
I've edited the image above in order to highlight the Bonelord area. All credits due to Tibia Royal.