Construction. Once you've got a portal room, a menagerie, and even a prayer altar, this can be extremely beneficial. The portal room is helpful, especially when you're beginning your journey as the member, and a lot of the teleports used by members are in the portal room. The POH can also be used to store items, including all tools, books, and tons of armour and other clothing.
Agility is also extremely useful reaching 21 is vital so that it is possible to take the Varrock-Edgeville shortcut. And getting it higher will be helpful in combating monsters, huge quest areas, as well as PKers (true encounter there). Making it at least 21 should be one of primary things that you do.
Summoning is an amazing capability, but you're not able to accomplish it right away. If you've not done so yet obtained 43 prayer, do it now with penguin points and the Troll invasion DnD before putting them into summoning. Being able to get a spirit terrorbird (level 52) is extremely beneficial and extremely useful. What I'm saying is...always keep your charms in your pocket. It's not worth leaving them in the dirt.
It is beneficial to grow herbs, but you can relax for a bit. It's not the only thing that matters: just don't ignore it. Learn to farm things and then gradually level it up. At around level 30/35 you'll be able to make some relatively regular cash from it.
Slayer isn't yet a great choice for power-training. It's best to do it only when you feel you want to. After you've reached 55, it's a good idea because it unlocks several useful things however until you get to the point that you're ready to do that then don't bother. It can earn a few dollars, but it's not really making money. At least not at a minimal level.
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