Not Necessarily a Carnie, but as a high school student I've worked full time at my local amusement park's games department through summers.

So, games...

First of all, the BEST way to win is to work at an amusement park in this department. They encourage you to play the games because when guests see employees successful in the game, it makes them want to play. This works in your favor because you begin to understand the gimmicks to each individual game. Also, you learn a whole bunch of other life lessons in your hours of boredom such as juggling, practicing dance moves to the music around you (when nobody is watching of course), and how to do absolutely nothing for hours on end.

Any game you are guaranteed a win, and can trade up/win larger prizes is almost always going to be the game where you'll get the most out of your money. If you were to play these once a day for a year vs any other game, you would probably get the most.

Avoid ring toss games entirely. If you MUST play one, have the person working there prove rings fit. Try to land a game IMMEDIATELY after the person before you, because it's likely the host won't have time to pick all the rings out. This actually reduces the bounce on each ring and greatly increases your chances. I find the most success from throwing multiple at once, but that's just me.

Any throwing game: Some amusement parks will allow you to practice for free on a slow day. If you can, do it. Have them show you the targets, and ask to see them try (if they are willing to).

Most targets in target-based games will have some kind of hair/fur attached to them making them look bigger than they really are. Do not be deceived. Aim directly at the target. How hard you throw does NOT make a difference. All you will achieve is scaring the shit out of the employee and probably making them more stubborn with you. Faaaar better to throw with a lob. With enough practice, these games are easily won.

Be careful with basketball games. Easily rigged.

Avoid games urging you to bounce a ball off of a plane into a bucket, because that shit is near impossible, though it looks easy.

Fishing games: Try to get a rod with a small rope. Say you're playing a game with water flowing in circles and little magnets you have to catch, with prize depending on some element of the magnet. The longer your rope, the more it will sway, making the game FAR more difficult. If they refuse to give you one like this, wrap the rope around the end of the rod to make it smaller.

If you are down on your luck, most employee will be generous... Most... Instead of hopping in between two similar games, choose one and play it a fair amount. Once you say your finished (after 4+ plays ideally) the employee will often give you another free attempt. I am Canadian though, so maybe don't take my word for it.

FOR THE CONFIDENT:

Racing games. You know the ones where the more people play, the larger the prize? Yeah. If you're smart, patient, and willing to accept that some people may be more experienced, you can come home with a LOT of plush because of these.

1: This is machinery, often as low budget as possible. It is likely that a faulty switch of some sort may either cause an easier win or outright lose you the game. It's important that you learn wich spots have this so you can thoroughly take advantage of that.

2: Always play the minimum for a prize. If there are 7 of you, and the next size up is 8, WAIT FOR 8 DAMMIT.

3: Most importantly..... Practice! Couldn't put it more simply.

4: Don't play for small (unless you just want to have fun). Remember, you're putting $2 in this game, so even if you're lowering your chances, the bigger potential profit the better.

5: Play with strangers. Don't grab 8 relatives. I guarantee you that the extra-large prize your children want so much are worth far less than $16.

Only play these if you're willing to accept defeat and not be able to blame it on the carnie.