Thinking two or more moves ahead

I remember starting out poker and getting a feel for the hands, knowing what was valuable, what draws were, and what cards were dead ends or traps. However, there were situations where I would execute my perfectly thought of plan, and then the other player would do something I didn't expect, and I would be stuck.

For example, I limp in with A 4 and hit my ace on the flop. I bet fairly large, and everyone but one folds. What now?

As I had not thought past the big bet move, do I bet again on the turn? How much? Do I check and fold if he bets on the turn?

If I hadn't prepared for these questions, then my responses were unsure and more often than not, I lost more chips than I had to.

So, I now KNOW what I am going to do with my hand pre flop before the flop occurs. If I have an A 3, and decide that that players I am playing the flop with are mostly conservative, and no calling stations, then the big raise occurs. What I do next is dependent on how the other players react, probably, unless I see a clear draw that could indicate why the other person called, I will fold on any turn bet.

I already know what I going to do in reaction to another players actions before they occur. This has lead to better decision making since the decision doesn't have to be on the spot and unsure.

Of course, you have to react to the other players, and be prepared for your plans to change suddenly. If you hit the flop with that Ace, but another conservative player bets into you first, then its probably time to switch plans and fold.

The other key which you will often see in beginners is not getting married to your hand, be ready to change plans. Sure, preflop a pair of Kings is a mighty hand indeed. But if you pre-flop raise is called, and an ace comes on the board, are you ready to fold? If a draw comes on the board, are you ready to change your plans now? I have seen numerous hands where pocket Aces or Kings are busted out post flop unecessarily due to one of two things:

Obvious made draws.
A normally conservative player calling or raising the pocket pairs aggressive bets.

These two key items, planning at least two moves ahead of your current move, and being prepared to change on a dime when other players actions and the flop provide new information work together to improve the decisions you make in the game.