Everyone who starts playing the game eventually wants to know the same thing: how to increase your Runescape combat level fast. After all, all the best stuff happens when you have the right combat level!
You can wear better armour, use better weapons, finish more elite quests, and get access to better areas. Most certainly, you can make more money by killing bigger beasts, and killing them faster.
The common misconception about leveling in Runescape is that you should work on the highest possible level of monsters that you can kill in decent quantities. Since XP is based on the amount of damage you do, and that damage is based on the number of hit points the monster has, it is natural to conclude that it is better to fight the monsters with the higher combat level. But this is wrong, for at least two reasons.
First, higher combat in NPCs does not mean higher Hit Points. Many times it reflects higher Defence or ability to do damage to you, so not only are you not doing more damage, but you are actually taking more too. This means more trips for food or prayer potions, and that is not the way to faster leveling.
Second, tougher monsters take longer to kill, and even if they have more Hit Points, it might be taking you a lot longer to do the damage it takes to kill them. What counts is not the Hit Points per kill, but the Hit Points per hour that you are doing. After all, you measure the time you play in minutes and hours, and not kills.
When I was on my last few levels before maxing out my combat skills, I did a lot of slayer tasks to keep myself motivated. One thing that I did differently from everyone else was to turn in the tasks that would take too long to accomplish. This meant that I never bothered slaying metal dragons, even though there were some nice potential drops there. I know for a fact that if I had kept all those slower tasks that I would still be waiting to get my first 99 skill. As it is I have 4 now (you can check my character Erikfrombc on the high scores for proof).
So what does this mean for the beginning player? Simply put, start low and work your way up. Whenever I make a new character I start out with chickens and stay there for a while. Not only do I get fast levels, but I also get prayer XP for burying bones, feathers that stack and which I can sell for decent money and better weapons quickly, and cooking XP from the raw chickens that I can cook in the nearby cooking pot.
I have a strategy that takes me from Level 3 to 50 in less than a week, with no more than 2 hours played per day. And with that I make enough money to improve my armor and weapons as I become qualified for them. Feel free to take a look at it at http://www.runescape-strategy.com/ . And try making a new character and seeing if it works!