I forgot the smiley face.

One place to start is to compare your range to your opponents range depending on position, board texture, preflop action and playing style.

For example: I raise 78s UTG, and button (22/15) calls. Flop is AK2. Does this hit my range or button's range better? Based on that, what should I do?

Or, the opposite: I raise AKo UTG, button (22/15) calls. Flop is 79T w/flush draw. Who's range does that hit harder? Based on that, what should I do?

The other thing to consider think about is board texture. Say you are considering CBing a JhTh8s board with AK against a loose donkish player (say he's 50/10 and calls any pair any draw). Take a minute or two and think about what hands he could call with that have a pair or a draw on that board and compare that to what hands would fold. Then you will start to get the idea about ranges.

This is just a starting point but I think it gives you some idea how you can start to think about these things.

Against very loose players it is almost impossible to put them on a range of hands on the flop, however by the turn and river you should be able to narrow it down somewhat. Basically against such opponents forget about hand ranges and just value bet. Later on once you have mastered the art of reading decent players then the loose ones will fall into place.

Tight/ABC type players are very easy to put on a range of hands, some assumptions you can make about most:

1) A cold call in the blinds is usually either a low/mid pocket pair or sometimes a suited connector
2) A 3bet from the blinds is usually TT+ or AK
3) A cold call in position is often a low/mid pocket pair or suited connector

Tight/ABC (tagfish) players typically fold hands like QJ or QT to a raise, even with position.

So based on these assumptions, plus any additional player-specific observations you can start to narrow down which kinds of hands they may have based on their preflop play.

From there you can start to combine this knowledge with a cbet strategy, in short:
Monster: Bet
Big Draw (eg [6h] on a [6c][2h] board): Bet
Weak Draw (eg AK on TJ3 board): Check
Big Hand: Bet
Weak Hand (eg second pair on a flop that has hit their range): Check
Air: Bet
Air with showdown value (eg AK on a 552 board): Check

If in doubt, ask yourself what hands will call me if I'm value betting, what hands that beat me will fold to a bet on this board.