Attack/Strength exp:
Vampire Slayer - 4825 Attack experience
Tree Gnome Vilage - 11450 Attack experience
The Grand Tree - 18400 Attack experience
Waterfall Quest - 13750 Attack/Strength experience
Fight Arena - 12175 Attack experience
Mithril Gloves:
Cook's Assistant
Fishing Contest
Goblin Diplomacy
Shadow of the Storm
-Gertrude's Cat
-The Golem
-Demon Slayer
Big Chompy Bird Hunting
Recipe For Disaster
Desert Treasure:
The Tourist Trap
The Digsite
Temple of Ikov
Troll Stronghold
-Death Plateau
Priest in Peril
Desert Treasure
Useful Quests:
Animal Magnetism (Ava's Accumulator)
-Ernest the Chicken
-Restless Ghost
Mountain Daughter (Bearhead Mask, also gives 1k attack and 2k prayer exp. Only do quest until you get mask to stay 15 prayer)
Horror from the Deep (Access to God Books, and 4662 range, magic, and strength exp)
Lost City (Good slayer instructor at 75 combat)
Ghost Ahoy (Ectophial, don't do if you want to stay at 15 prayer)
Priest in Peril (Req. for DT) 1406 Pray xp
The Restless Ghost (Ava's Accumulator) 125 pray xp, DONT BURRY THE BONES YOU GET
these are the only two quest you can do for prayer xp. Will keep you at 13
Also note that if you do Mountain Daughter to not finish the quest, Just get to the point where you receive the bearhead and telly out.
DT is basically required for a Gmaul pure IMO so with low prayer you will need someone to help tank for you as it can be pretty challenging.
That should give you a good start though. Remember to quest as much attack and strength XP as possible. Also CB bracelet is cheap now so you can save time and use that instead of mith gloves.
If i've missed anything let me know (Other Sythe Members)
Good luck man! Gmaul pures are fun