I guess it would be important to create a new steam account. I mean, if you are going to make ELEVENTY BAJILLION DOLLARS, you have to start from somwhere. Make sure to have a snappy username, something like ArchDuke MoneyBags would work well.
New Steam Account Dedicated to this business venture.
Several months at least.
A couple bucks in your steam wallet.
A computer that can play TF2 at 60 FPS, med settings at least.
A fast, low ping internet connection.
Good accesories. (Good desk, monitor(s), mouse, keyboard, headset)
Constant supply of food, preferably food that can be consumed quickly while waiting to spawn or load.
Something playing in the background to entertain you. Music, TV, Radio, Twitch.tv, doesn't matter, anything can help.
Moderate skill in playing multiplayer First Person Shooters on the computer, without a gamepad.
Lack of responsibilites. Except for Mr. Fluffers, you need him.
A friend (AKA New Business Partner) that has these things or shares your computer, and is willing to help you out in your quest. This is optional, but can be worth it. This must be a very trustworthy person, you are starting an entrepreneurship together.
Why are we going to create a new steam account you ask?
Well, if we are going to make a lot of money by getting items and stuff, we shouldn't include our work items with our personal items. Unless you plan on selling your items in your primary account, it's best that you create a second account for your moneymaking ventures.
Once you create your new account, you will have to buy a game in steam and an item in TF2. This will activate your account for purchases. Steam has this weird thing where you have to buy something to get free things I guess. Just buy the cheapest full game and TF2 item you can find.
Make sure you have TF2 installed, that's kinda impotant. Perhaps I should have added that you need a decent computer for this guide to work. Sorry, but a netbook running TF2 at 15 FPS isn't going to cut it.
Once you have your second account ready, start playing some TF2!
You could use your primary account if you want, but I'll explain some more why a new account would be best later.
2. Playing TF2
The Deadly Foes
Exhaustion due to lack of sleep.
Need to use restroom.
Horrible Internet Connection/LAG
Responsibilites forced upon you by others
The other team
Desire for human interaction
Do everything in your power to solve these problems. This is where having a friend helping out really helps, they can take over, cater to your needs, even provide emotional support.
Get Better At TF2
Don't waste your time AFK! Spend it reading up on TF2 strategies, watching videos, or listening to commentated videos on TF2. Make your life all about TF2. Study TF2 in the shower, listen to commentaries as you sleep. Eat TF2 O's* for every meal of the day. But of course, the best way to get better is to play the game. Don't play any other game, and don't play on your personal account, that's what you do when you are done with this moneymaking venture. Play whatever gamemode you want, make sure it is online. If you host your own server, you can play on that, just see if you can enable bots if there aren't many players. The important part is that you are getting kills. You could set up sentries and dispensers to get points while you are away for just a moment.
* TF2 O's Coming to a store near you soon!
By playing the game, you should start unlocking items as you play. An important thought to consider is if you should spend money for items.
Should I buy/pre-order a game to get extra items in TF2?
Not sure about this. I pre-ordered CS:GO and got a special sniper that looks like the AWP. It's essentially a reskin, it's no better than the standard sniper rifle. I've seen it being sold on the market for about 3 bucks a piece, soo feel free to do so.
Should I trade items?
Sure! Just be smart when you trade! Don't give away items. Don't be afraid to ask for items or trades. There have been times where I've been given crates for free, just ask.
Should I buy and sell items in the market?
Only if you are really going to use the items, or can sell them with a markup price. It's not too hard to get an extra 5 cents from micropurchases. If you are lucky, you can get much more profit. I've got as much as 50 cents from a single crate.
I got a new gun. Should I get rid of it or use it?
Try using it. If it's a good upgrade, keep it. If not, trade it, or craft it into something else.
Trade or craft?
Trading can be a good way to get exactly what you want. However, crafting items into others, such as scrap, could increase the value.
4. Making Profit!
There are three main ways you can make a profit from your TF2 playing adventures.
Sell off your new account that you made.
Sell off your items in the Steam market, and exchange the steam market money to real money.
Trade your items in the Steam market with someone for money.
Selling off your account.
NOTE: Brush up on those walls of text that you had to agree to when you created your account, it may say that you are not allowed to do this.
Because this may or may not be allowed, I am not going to tell you how to sell your account, as it may get you banned. However, there may or may not be information out there on how to do something like this.
Selling off your items in the Steam market.
This is pretty simple to do. Just make sure you have a good price set for your items. Compare other prices, and aim for similar ones. Set your price based on demand or how rare the item is. For example, crates can sell for 0.01 to 0.25, while a melee weapon for dota 2 can sell for $15.
Getting money from your steam wallet.
I'm not sure if you can gift steam wallet money yet. Until then, you could use the steam wallet to buy games and gift them to others. You could gift the items to friends in exchange for real money.
Trading steam items for real money.
I'm sure that there are websites and communities out there meant for trading items in TF2. Look around for them, and remember to aim for a profit.