1. When you make a bet, it generally should be between 1/4 the pot-size to the pot-size. 1/3 to 2/3 is a great standard range, with the occasional small 1/4 pot-bet or the occasional large pot to over-size pot bet. Example: when the pot contains $10, you should at least bet $2.50 and more typically from $3 to $7. Occasionally, one can make a small bet of $2.50 or a large bet of $10 or more. But most bets should be between $3 and $7.
2. When you raise, it generally should be between 2X to 4X the previous bet or raise amount (remember, by rule it can never be less than the original bet or raise amount.) Example: if a player bets $2 into a $4 pot, if you raise you should make it at lest $6 to go (raising $4, or 2X their original $2 bet.)
3. When making a pre-flop decision, your position is just as important as the cards you were dealt. Example: At a full-table (>7 players) and you have Ace-Ten off-suit in early position (left of big-blind, which also called under-the-gun) you should typically fold. However, if you are on the button (best position) with Ace-Ten off-suit, you raise with the same hand (if no-one has raised before you), and if player just to your left raises, you may even re-raise them with Ace-Ten off-suit. So the same hand that is trash (foldable) in early position because a raising hand in late position (and sometimes even re-raising hand). An indication of how important position is.
4. When making a Pre-Flop decision to raise, call or fold, it is usually better to raise or fold rather than call. After the flop and especially on the turn and river, the situational complexity is such that all 3-options need to always be considered, but even then aggression (betting and raising) usually edges out calling on close decisions because calling only wins when your hand is best, while betting and raising can win two-ways: (1) your hand is best (2) the opponent folds. Example: Let’s say you are sitting to the right of the button (also called the cut-off) at an 8-player game and the two loose players to your right limp into the pot (meaning they just pay the minimum big-blind and do not raise). You have 3c 5c (three of clubs and five of clubs), If you decide to play this speculative hand, you should raise a decent amount with it rather than “limp” or call. (1) you may win the pot immediately. (2) you often get the button to fold and then you are best position. (3) You can win more frequently after the flop if players believe your hand is stronger than it is making it easier to bluff. (4) when you do hit a great flop the pot is bigger. (5) It allows you to raise with premium hands and players have a much harder time knowing what your holding, KK or 35.

REASONING

1. The vast majority of the time there is no reason bet bet less than 1/4 the pot or greater than the pot. If you are considering betting less than 1/4 the pot, you should choose between checking or betting 1/4 the pot.
2. If you do not raise more than 2X the previous bet/raise amount, you typically do not get the fold equity you often desire OR you don’t get the value you often can get and in the worst-case the opponent makes no mistake by having the odds to call to their draw.
3. “Position” determines if you have to make a decision before other players or after other players. Being “on the button” is the best position, because you are last to act, and get to make your decision after everyone else has made theirs. This is a great advantage and allows you to play a larger variety of hands. Being to “in the small blind”, just to the left of the button is the worst position, because you are the first to act and have to make a decision not knowing the intentions of the other players. This a great disadvantage and requires you to play a smaller amount of hands (you should be folding more often.) The position continues to improve as you go from the small blind (left of button) all the way to the button.
4. This is because when you call you are typically counting on your hand to be the best by the showdown, and when it is you the pot will be smaller because you were just calling instead of raising. When you raise you can win the hand by the other players folding OR by having the best hand by the showdown, and when you win, the pots are bigger. If you cannot get yourself to raise, you should seriously consider folding instead of calling.