Holistic thinking is something that escapes most players, and is generally what separates marginal players from great players. Holism, is a way of thinking in that the properties of a system are not a function of it's separate parts, instead the system as a whole determines the properties of it's individual parts.
Now if you ask me, that describes a poker table perfectly. The table is the system and the players are the individual parts. A good player is going to have their playing style defined by how the table as a whole is playing. Every time the properties of the table change, so should it's individual parts. So few players realize this. They have a set gameplan, and stick to it rigidly. While they may win, they surely arent maximizing their potential. You need to realize that how you should be playing is a direct function of how everyone else at the table is playing around you. My stats average out to about 17/14/3, but I don't sit down and play close to a 17/14 style every time. I have sessions where I'm playing 9/7 and I have sessions where I'm playing 24/21 and I have sessions where I'm playing 33/28. How I play is a direct result of how the table around me is behaving, and so should you.
Holism, in a looser sense, also applies to individual hands, with the hand being the system, and the streets being it's parts. You need to be thinking of the hand as a whole, and base your decisions on each street by how you want the hand to end up, rather than just acting on each street as it comes up and ending up with a finished hand. You need to have a plan for a hand, and each decision you make is because of your overall plan. Professional No-Limit Hold'em by Flynn, Mehta, and Miller
does a great job of teaching this way of thinking about a hand and how to plan hands out.
Basically, they have a two step process. Based on your starting hand, you have a target Stack-to-Pot Ratio (SPR) that you are looking to get on the flop. Then based on the SPR range that you are able to achieve, you play the hand out accordingly. This is a very basic, yet very effective, way to approach hands Holistically. By having an overall plan for how you want a hand to play out, rather than just reacting to situations, you're going to be much less likely to make mistakes.