That's the OSRS gold majority of it. To start off you should go to the 2nd greatest room you are able to enter and start opening up the urns. Be carefull and watch your own time. When you believe you have sufficient time to hunt all of the urns in the next room do it. Be certain that you receive each one of the urns in the last room you may enter. It means more xp. I dislike the tombs because I am such a low level and may die from the mummy or the bugs.
What to wear: I typically wear nothing and whatever can lower your own weight. But if you opt to loot the tombs I'd wear some decent armour. Your Invi: It ought to have 1-3 anti posions or more if you prefer. And about 1/2 of your Invi with some good food. Don't bring in sharks or swordies, because it will only be a waste. Things to keep: Really nice you have done Contact. I am having trouble because of my combat level. Anyways Since you've done Contact I would store it all. Or simply save the Golden ones because there those with the maximum value. In addition, I think there is another pursuit where you are able to note all the statues (except Golden) and sell them to the guy by the Agility Pyramid. I really don't remember what quest.
I'm not really sure what happens when your from the last room. I believe its exactly like any other space but It has a good deal more XP in the loot making it worth while. Greatest Stragagy: Your timed 5 minutes as soon as you enter the first room. I would search all of the doors to enter the next untill you reached the second to last room you may enter. Make sure to see your own time! Then when you feel you have enough time to hunt all of the Loot in the room do this. Hunting the Urns is the quickest XP you can get. Also the tombs have the loot but folks like to seek those for the very rare to get employees that's at the tombs. I'm not so sure how much is your staf, but I asume it's buy RS gold very pricy.