If you have 90+ attack and strength, then melee would be the best choice. Ranged setup though would go something like this... Items that RS gold are equipped - Neitiznot (for praying and defence bonus) Also, any boots you'd like (ranger or snakeskin will make the most sense after that, followed by bandos / white for prayer),
Method - Stand directly in their direction, keep away from melee and keep an eye on them. They'll probably melee the majority of the time as your d'hide / arma will tank most of their magical strikes. The only damage you'll take usually is their ranged strikes.
I think, first of all, you need to construct a throne area and build a floor in the middle of it. Also, you need to build an oubliette room beneath it. It is also necessary to build an entryway to the trap. After that, there are two different ways of entering the cave The first is a large cave entrance you construct in a beautiful garden. The stairs are a flight of stairs inside an area.
When you have built one of the two rooms, you will have the option to build a lower level room that, and there must only be one option available for this. Once you have built the room(s) you are able to build in normal construction mode, and build treasure rooms, dungeon passageways and junctions, or any room from above you'd like to create down below.
If you've not done it, this Love Story quest unlocks a new type of dungeon that adds a variety of new dungeon guards you can place in the room which include scarabites, black demons, iron dragons etc. Also, most of these new creatures are more affordable than the traditional hellhounds, trolls and dragons etc.. If I've missed anything, don't hesitate to contact me for clarification.
Lardar pretty much summarised his best practices, but in order to create a plan , we'll have to know the level at which you're at.
And, of course, good luck! It's up to you how you'd like it to be done Personally, I am not a fan of runecrafting , and don't have the money, which is why I slay constantly on the hunt for effigies to use on runecrafting. Also, I'm helping people to get their RC and effigies (91 and up, I'd recommend this because it's a no-cost 30k rc daily XP)
I'd use the penguins as for a boost once a week, since it all adds up into a very high XP count in the time it will take to get to 99 Runecrafting. Also, when the free trade system is back, we will see the rise of Air, Law and Double nature running again as well, which could be an ideal option, instead of cheap OSRS gold simply sit at the altar for the whole day and let others be the source of essence to you.