My fastest time is getting one in under 5 minutes. My slowest time is not getting one for 2 days. It all depends on luck really. Just wield a ring of wealth to boost your chances.
Hellhounds
To get it for free you have to do Clue Scroll lvl 3. It is rare reward from it so you wont get it at once. You have to be member to do clue scroll.
Clue Scrolls are random drops from monster that will lead you to a hidden treasure There are 3 different types of clue scrolls, the higher the clue scroll, the better the reward: lvl 1: These are the easiest clue scrolls, they are dropped by low lvl monsters and the clues are easier to work out lvl 2: These are medium difficulty clue scrolls, they are dropped by medium lvl monsters, and will have a mixture of lvl 1 and 3 clues. lvl 3: these are the hardest clue scrolls, they are dropped by high lvl monsters, and will be the hardest to work out. When you work out a clue scroll and search the chest, create or dig in the right spot, you will either get: another clue scroll (Then you work that one out) or your treasure. For more info check here: http:/runescape.wikia.com/wiki/Clue_scroll
none but you should have a high combat level
there is no fixed rate of drops for clue scrolls but it can range from your 2nd kill to your 1,000th kill
A good way to get a level one clue scroll is to pick-pocket H.A.M. members until you get one.
You can kill certain monsters for a level 1 clue scroll. Refer to tip it & go to treasure trails where you should then see a list of monsters that drop each level clue under "Basics"
Warriors Guild, same place where you get defender, on those giants.
yes it is better than dragon plate. also, its more expensive
lvl 3 clues are dropped by a multitude of monsters, but ones that ive gotten them from include hellhounds, black demons, greater demons, and metal dragons (which also drop elite clue scrolls, i think. At least Mithril ones do.)
They drop level 2 clue scrolls.
Treasure trails are not quests, but mini games, and they cannot simply be started at a certain point. To begin a treasure trail, you must first find a clue scroll that will lead you to the treasure. If you are looking for a level 1 clue scroll, then there are several easy enemies that can be killed to obtain one. Possibly the easiest, are the warriors in the Palace at Al-Kharid. Once you have one, simply follow the instructions. Harder clue scrolls can be found, and they go up to level 3. These are harder to obtain and complete.