Hey. Everyone is different. Is there really a "correct" method of killing something? My opinion is to simply hit them with your best weapon and gear, all the while raising the intensity! But then again OSRS Gold, I've not killed one. Just cancel what is hardest or what you dislike. Why should you keep doing something that's taking too long?
I'd cancel Black demons. I've heard that they are not good. Kalphites are swift and will earn you a few quick points for slaying. There isn't necessarily a lot of slayer experience however, it's quick task.
LRC is very profitable It's what I've heard. They make around four or five dollars for every job that is pretty good over the long term. There's also a chance to look at the Patriarchs, which will automatically shed around 200k. Pretty dang good. They also provide a great experience I think.
Don't fret about the mineral content. They can be a time-consuming process, and my view, is not worth the time and effort. Ugh. Hellhounds. I'd block them. They're only good as clue scrolls. Charms made of gold are... They can be re-enforced, however.. It is not recommended to block bloodvelds. They're great and they are very fast. There are no drops Buy Old School RuneScape Gold, however. If you're in need of a guide to any monster, check out this excellent guide designed by Azarath.