I would recommend using OSRS GP an emerald/broad (e) setup, start by using the emerald (e) to poison, then switch to broads to finish it off. Each kill is worth around 20k or so. I myself do 2 kills every time (using prot and eagle eyes at times) melee occasionally) then return to the home port, recharge at altar, use the fally portal and bank and go back in time in time for the next one to happen.
Hey. All people are different. Do you really have a "correct" method for killing something? I would say, simply smash them with your most powerful equipment and weapon, while raising the intensity! However I've not killed one. Make sure to eliminate what's hardest and/or what is bothering you. Why keep a task which isn't efficient?
I'd cancel Black demons. They're not good. Kalphites are fast and can get you some quick slayer points. It's not necessarily a slayer's experience, however, it's still a quick task.
LRC is very profitable It's what I've heard. They make around four to five thousand dollars per job which is quite decent over the long term. There's also the chance to take a shot at the Patriarchs who automatically drop about 200k. Pretty dang good. They also offer a good experience I think.
Don't fret about the mineral content. It takes time to process them and, to me, is not worth losing the experience. Ugh. Hellhounds. I'd block them. Only good in clue scrolls. Charms made of gold are... They are able to be fired.. I wouldn't recommend blocking bloodvelds. They're amazing and fast. There are no drops, however. If you're looking for a manual to any monster, check out this wonderful one made by Azarath.
I'm almost done with old school rs gold The Void Stares Back quest However, there's a single problem: The Pest Queen... I've tried four times, and this is a quick overview. Attempt 1: D platelegs, d'hide top, neitz helm, d def, korasi sword. Inv: 5 praying pots, rest rock tails. The Pest Queen to about half-way but before I went over my limit, had to port. Attempt 2: Same armour. Inv: 5 pray pot, super str pot, ambush scrolls, spirit Kyatt, rocktails.