The bet size you opt for can vary a lot, and stakes themselves might change within a game. Here are a few things to consider that you might find useful you gamble online.
Bet Sizes and Budgeting
Gambling's fun and exciting, and optimal bet sizes will vary according to how much disposable cash you have. However, there are a few other factors to consider. Some people are comfortable betting with small stakes but, even if they can afford it, higher stakes stress them out and make it harder for them to make smart decisions. It also depends on how often an individual plans to bet. If you're intending to play three hours of craps a night, then (all else being equal) you should play for smaller stakes than if you play one hour a weekend.
Everyone dreams of winning big, but your wallet and not your wishes should determine your bankroll.
Fixed or Changeable Stakes
Something to consider is whether a stake is a fixed or a changeable amount. Poker, for example, allows raising from an initially small bet size. Slots, on the other hand, can have variable stakes but once it's decided that's the amount fixed for that spin. Related to this is the time involved. Spins can take a much shorter amount of time than a round of cards (although blackjack tends to be pretty quick), and you might even fold fairly often without putting in any bet at all.
For a complex game like roulette you might take a differing approach to wagers for different types of bet. A red/black bet (almost 50/50) might see you put down a larger stake as there's a higher chance of it coming off, whereas a numbers bet might be for a smaller stake, given the lower chance of it coming good. Don't get tied down to one specific stake. You can make it smaller if that fits the bet or the game you're playing.
Limit and No Limit Bet Sizes
Poker is one of the biggest casino games, and raises can happen in a limit or no-limit way. To explain, PLO (pot limit Omaha) has a pot-limit on betting. You cannot go all in. No-limit Texas hold 'em, by contrast, has no limit (hence the name) on betting. This significantly increases how much money you might be throwing down in one hand. Because of this more volatile bet size, it's easier to burn through your cash quickly. The flip side is that if you're playing well or fluking great hands you can end up a lot further ahead than you would with a limited game.
All of us have a limit when it comes to wagers, and discipline is important for gamblers, especially poker players. Decide ahead of time how you're going to handle it if you get wiped out, and don't be afraid to walk away if it just isn't your day.
Ultimately, the optimal bet size for an individual comes down to their wallet, their time, and their temperament. Keep cool, and only bet what you can afford to lose.