How should recreational players go about reading situations involving cards and their opponents? Well, carefully, but not in such a way that it over-complicates things. No less an authority than Doyle Brunson, a former world champion in poker, said "Stick to your first impressions. Have the courage of your convictions."
What this basically means is, don't out-think yourself at the poker table. There are obviously a lot of things going on at once when you sit down at the table, and those things can have a way of conflicting with each other. You have to be very careful in the way that you approach any situation, but once you feel as if you are ready to make the right decision, by all means make it.
We know this can be difficult, since this is not a game like blackjack where there is a correct decision to make and that's the end of it. In poker there can indeed be so many variables that it can be dizzying. When you get into situations where you are contemplating putting someone "on" a hand, you have to have an idea as to what kind of hand they have. Don't underestimate what you are holding. And by all means, don't let your ego get in the way. That means, while you should be confident in your position once you have taken it, don't get an over-inflated sense of where you are or what you can do.
Flexibility is very important, because these situations are dynamic, not static. But at the same time, don't be all wishy-washy. If you are unsure of yourself, don't stay in. And certainly it can be very useful if you are aware of your own weaknesses. If you are not, this is where you can really lose an edge, and lose yourself. If you have a pretty good sense of you own biases, you are going to understand how to play "counter" to them, and you will wind up being more difficult for opponents to deal with. Remember - your opponents are trying to put every bit of psychology on you that you are on them.
If you follow football, you are well aware that teams study their own tendencies because they known that other teams are studying them, and will play accordingly. We admit that these are awfully hard to shake, because when put in a certain situation, we are all going to lean toward what works best for us. So mix your [lay habits up, and don't get out of control.