Ever wondered why elvemage was only around level 80 and could easily own so many other pkers without much difficulty? It was because he focused on mage and range, not everything else. Pures are players that train usually only 1 or 2 combat related skills to keep their combat level low and continue to be able to hit a large amount of damage.
In this guide you will learn how to make a mage/range hybrid (same as elvemage) except on f2p. If you follow the instructions right, you can end up with a character with 70 mage and 70 ranged and around level 50 combat for the low-level crater in Bounty Hunter.
The main idea of a range/mage hybrid depends on the magic required to bind and finish the prey off (with at least level 59 for fire blast, 16 damage max) or against warriors with armor that easily counters against ranged and the ranged to deal damage (fire blast is very costly).
Let's Get Started Then!

Start off by killing chickens in the chicken coops north of lumbridge with the runes and bronze arrows you already have. Pick up the arrows you drop because you don't have many and pick up the bones as well. Do NOT bury the bones you picked up! With your remaining runes (hopefully you're at level 3 magic or higher) cast confuse on the chickens or ducks.
Go back to lumbridge and ask for arrows and a training bow from the ranged tutor. Go kill some more chickens, and do the same to the bones as last time.
Now head towards Varrock and sell everything except your extra runes and shortbow, don't forget to sell the bones which are worth around 80gp each at the time this guide was written. Use your remaining money to buy food on the Grand Exchange (preferably wine, trout, or salmon).
Go through the stronghold of security in barbarian village and the stronghold of player safety between edgeville and barbarian village. If you ever have any difficulty with any party of this guide you can always check some runescape fansites, such as tip.it, zybez.net, runehq.com, etc. This will give you a total of 20k, protective gloves, 500 exp in any skill (use it on magic, its the most costly), and some other stuff. Now go buy yourself the best shortbow you can use (if you don't already have it) and some bronze arrows.
1-20 ranged
Train against chickens until you reach 20 ranged and then buy as many iron arrows as you can.
21-45 ranged

Take all your iron arrows and go to the stronghold of security. From the start, go down a room to the room of goblins and then east one to the one with minotaurs and wolves. Kill the minotaurs with accurate mode until your ranged level is high enough to not waste any iron arrows in rapid mode against them. If you get dealt too much damage at the beginning then you can hide behind the fence and then go over to pick your arrows up.

Another method is to train against the monks in the monastery west of edgeville. These monks have low defense and could heal you if you are low on hp. The only con for this is that they do not drop arrows unlike the minotaurs so it can cost a bit if you're low on cash.
46-70 ranged

By now you should have a good set of armor for your ranged level. Wear a leather coif, a strength amulet, leather body, green dragonhide chaps, green dragonhide vambraces, a maple shortbow, a cape, 1000 bronze arrows, and boots. Buy 500 wine and use the rest (leave some money in case you need it) on bronze arrows then head toward Port Sarim with 60 coins and an inventory full of wine (you won't need attack levels for ranged, lol). Go on the ship to Karamja and head towards the volcano. Find a crevice to enter the volcano and head left then south towards level-82 lesser demons.
At first the lesser demons will attack you, so you might have to run around a bit until they get "used" to you and stop being aggressive. Always use the stalagmites for hiding from the lessers while ranging them (they're quite large for the holes you need to get through, plus npcs can easily get stuck). Always turn run on and use rapid mode. When you kill one go pick your arrows and loot up. Eat whenever you have to, or you will die because you have only 1 defence even though lesser demons have low attack.
Lessers are the best monsters to train against experience and investment-wise until level 70 ranged. If you do not like them then you can train against guards, moss giants, or other creatures, but this is my recommendation for the fastest way to level up.