First of all, I believe the Runcrafting minigame called the Great Orb Project, is the best cash for f2p. So get 50 RC ASAP! Train Atk and then Strike Men on Edgeville. Then, you can go to The Guards in the palace of Al Kharid, and finishing off with Flesh Crawlers in RS gold the second Stronghold of Secruity. The best spot for Flesh Crawlers is the South-East corner of the room.
Range: You could do this on men also, or even at cows, using the safe spot between the two bowls of food south in the Lumbridge cow patch. After hitting about 20 or so, you can move onto the Minotaurs within the first level of Stronghold of Secruity. Find a room to your liking and safespot away from a fence.
Iron arrows fall off quite often, so it's basically free training. About about 40 to 50, you can train for a while at Hill Giants until 50. Once you reach 50, head back to the flesh crawlers inside that south-east corner of the room. They are located in the corner of the closest door to the wall. This is applicable to both doors. (You are able to easily obtain 75 Str/Range at flesh crawlers.)
If you're in the market for food take a trip to world 1 where fishermen power fish and offer free salmon or trout. Magic: Train on the dumbies of the mage until it stops you from doing so. Once you have achieved the magic level needed for a few curses. You can cast these curse spells on the Zamorak monk in the Varrock Castle, directly next to the stairs.
Once you have reached the magical level ( I believe it is 25, I believe it is) you can cast the Curse spell on your Zamorak monk. Once you've reached that level you can also superheat (really rapid xp) and break even if you make steel bars) and high-alch. Leave prayer alone, maintain your target at 40 (45 if you get the two-hour gravite).
The glacors drop three costly sets of boots. I think they're 8M, 15M , and 22M. They're dropped, in the average (from my sources I'm not sure - confirm my assertions if I'm off) at least once every 500-1000 kills. Glacors are not the quickest things to get rid of (albeit they're not the slowest of all).
Lets say, then, Glacors decrease by approx. 15 million for every 500 kills. I'm using 500 because there are also other drops (notably shreds) and this can help to account for those drops.
Items dropped by Barrows are, at an average of 1:15 iirc. The items vary from 50K to 1.7M at present. Plenty of items are around 1M, and even below however, a small percentage are in the upper 1M. Let's say 1M for every 15 runs - this accounts for runes, and similar items as well. Barrows is a very low cost option and you end up with cheap OSRS gold a lot of blood/death runes in case you use Polypore (which is something you should).