By using the highest level spell you can.
Higher level spells give more experience.
Use fire strike.-lvl19 Use water strike or earth strike if possible. lvl1 Use wind strike.
By fighting. That will increase your levels in different skills, which will in turn affect your combat level. Note that the higher you are, the slower it will be to advance.
That depends entirely on what skill you are raising.
Methods for training experience are either fast and expensive, or slow and cheap.
Ranging ogres north or ardougne is a good way to gain fast xp at these lower levels, using a magic shortbow and the highest level arrows you can weild. No hes trying to get to 50 he can't wear a magic shorbow
There's a program called an auto-typer, you can use to talk really fast in runescape, however the use of these are against the rules so use at your own risk.
I assume you want to level up combat. Same as in the paid game - fight a lot. Your combat level is also influenced by your prayer level; but in f2p, your fastest option is burrying big bones, which is still rather slow.
Your able to get your attack up fast if you attack and kill animals or people above your level you gain more experience. When I played Runescape I used to do this alot. It's great fun isn't it!
No, it goes really fast after the beginning.
By doing magic. Personally I do a lot of combat, but many players prefer repeatedly using either High Alchemy, or Superheat Item. In no case will this be fast, however. It takes a long time to get ANY skill up to level 99. Other methods are using humidify and planking which require the lunar spell book and also using the stun spell which is on the normal spell book is fast xp but can become very expensive.
Level 85. It isn't really important: at that level you can make money about as fast mining clay, than mining rune ore. The rune ore is worth a lot, but it also takes much longer to get.
hill giants, bank the bones and you'll make money fast.