RuneScape

I like wcing the best and fishing is ok and i dont know about mining

mining is good money if you like it and will stick with it... it can get pretty boring after a while, because you have to keep clicking and stuff.
RuneCrafting is also a good money maker, but you will need a higher level to gain profits.
WoodCutting is really good once you get to around lvl 70 (lol)
So is fishing if you're willing to walk quite a distance (fish lobs and swordies at Karamja and teleport to Falador to bank; then after u bank, walk back lol).

Like the other two Woodcutting is good. But any extracting skill (fishing,mining,woodcutting,etc) at a high level gives good money

I dont even know what trade f2p is could someone clear that up for me XP

I would say woodcutting is by far the best skill to make money with, i advise you to cut normal logs until you can do oak. then stick with oak until lv 40 or so then do willows until 70-75 then chop yews for a lot of profit, the other skill i find useful is smithing, buying ore, then smithing to make loads per bar.
Hope this helped you

by the way Boing F2P means free to play

Mining - ok skill to raise money, only best if you have 40+ mining though.
Smithing - a good skill to raise gp, best combined with mining, but you'll get gp slower, but you get more. Smithing is best even with 1 smithing, just smith bronze bars, also when you have 48 smithing, smith steel pl8 and sell.
Wc - a nice skill to make money, only good at 60 wc. Yews are the most expensive logs, worth 350-500 ea.
Runecrafting - turns out good when you can craft at least 6 air runes per ess.
Fishing - 1 of the best skill to make money. You can make a lot of money starting from at least 45 fishing, u only need 40 fishing to start, but will take much longer. It is NOT recommended to cook them, so just leave them raw. Raw Lobster - 350-450ea Raw Swordfish - 400-550 ea
Crafting - a nice one. you have 3 options:

Long, Expensive, and kinda boring way (crafting 1) Notes: you will need at least 500k to start this. Buy 1000 cowhides at the ge for 100k. Go to al kharid and tan all of them to soft leather, then sell them for highest price, when not selling, lower it a little.

Super long, Not expensive and boring way (crafting ?) Mine some ore and bank them if you can, try to mine a gem if possible, then cut them, sell them and higher the price.

Medium, Expensive and not so boring way (crafting same as 2nd option) Buy gems in the ge and cut them, easy and simple. Oh yeah, don't forget to check the GE database on the runescape website. Sometimes the uncut gems are more expensive than the cut ones, watch out for that.

Really nothing is THAT good for making money on f2p, if you get members and do runecrafting 99, then you will end up making well over 300mil gp for it.

The BEST way to make money in f2p is to man up and get your mining level to 85 so you can mine runite. (powermine iron in Al-Kharid for 32k xp per hour, this may take a few weeks)

The only place you can find runite in f2p is in level 46 wilderness, northeast of the caged lesser demons. (2 rocks)

To protect against revs, wear armor with high mage def (greeen d'hide), pray range protect if you get attacked, and RUN! (you might want to bring food too)

Since runite respawns at a lazy rate, (about 17 minutes on average) you will have to hop worlds continuously until you have a full load (should take no more than an hour) which you can sell for about 400k per load!

Mining+smithing,its long but makes lots of money.

Wcing... you can make 400k a week at 65+ wc

responding to my first post:silver ore can be sold for over 500 gp each,OMG! i thought gold(over 400 gp each)was a lot

mining+smithing
u need:
30+mining
30+smithing

first mine about 200 coal and 100 iron then turn them to steel bars then note them and sell them on G.E for 800 gp a bar
800x100=80k

also the 500 gp silver ores were only for like 2 weeks then it went back to 300 gp

cooking is okay, you buy like 100 or so plain pizzas, 100 anchovies and make them into anchovies pizza. I got this form rune wiki.

Ok lemme clear this up for a few newbs who know it all about woodcutting if youre 60 on f2p ur yew logs dont go any faster even when ur 99 ur still at the same woodcutting speed as a lvl 60 and im sure of this because im 72 and my bro is 99 and i still outrun him sometimes at woodcutting were always using a rune axe and also its been confirmed by 2 sites and jagex themselves u dont woodcut any faster unless u use a dragon hatchet or that tool wich is an hatchet and axe in one combined this is also my first post on gamefaqs and i will be making a guide on how to level magic 50% cheaper