Start off by getting 36 woodcutting, 31 crafting, 15 agility (+ summer pie boost for mountain daughter) OR 20 agility (+summer pie boost for grand tree) and 43 prayer to be able to do the following quests:
- waterfall quest
- vampire slayer
- fight arena
- tree gnome village
- grand tree (higher points/hr) OR mountain daughter (slightly higher XP/hr)
I, for one, don't think MTD is that much higher XP/hr than demon, and demon gives more points/hr meaning you make more money (back) over time. So, I'd suggest you to go with demon, but feel free to do otherwise.
After you've done these quests you'll end up at around 45 attack and 30 strength. From here I would usually just go train at rock crabs until around 70/70/70. Don't forget to upgrade to the best possible weapon at your level, brine sabre being the best @ 40 attack and obby sword + berserker necklace being the best @ 60 attack.
Then, once you've reached 70 base melee stats, you get to choose your method of doing NMZ. Here's a few:
- dharok w/ absorbtion potions > requires very high concentration, low cost, highest XP
- guthans > requires very little concentration, low cost, low XP
- ss w/ prayer potions > requires little concentration, high cost, high XP
I usually just go with the latter because it enables me to afk while training. If you feel like watching your client 24/7, go with dharoks, as it's the fastest XP possible. Though, you'll have to do a few extra quests for that method.
I could go into much, much further detail (inventory setups, rock cake guides, bla bla bla) but I'm sure Google is just as good at explaining these things than I am.
Hope this helps, lmk if you need help w/ anything else!