On free online poker sites you'll come up against good, bad and actually stupid players though maybe a few more of the latter 2 on the free sites than on say a $5000 buy in table in Monaco!
Good, bad, stupid no matter there is one playing style you should adopt to play successfully against them all and that is KISS, or rather that is, Keep it Simple or Straightforward; or KISS - Keep It Simple against Stupid players!
Lets look at some examples:
With A-10, for example, would you dare to go up against a strong player in a flop A-8-3? Yes sure if it's free poker but what if there's a lot of cash on the table?
You can just call-call-call, or bet and hope he does not play strongly. Why? Because if he's a strong player, you can put him on A-K, or an Ace with a stronger kicker. If he moves all-in, you know what to do. Scamper, and wait until you have the A-K, or maybe a Set.
Here you are set to thinking. Does he really have A-K? Or just J-J with which he is willing to take to showdown but is not so willing to call a large raise with? Or maybe 8-7, because he believes my bet on the Flop is just a continuation bet and he calls?
But against five or six weak players, you may have to ask the same questions five to six times. Does he really have?-? (for Player 1). Does he really have?-? (for Player 2) just?-? (for Player 3) so on, until your mind is now drained, and you are finally knocked out with someone holding an A-8. So are at least three others.
Let us look at another situation now, with a Board of 5-6-J-Q-8.
You have K-Q. A strong player probably has A-Q or K-K, or J-10, or something special, like 7-4 (usually suited). You might as well fold your K-Q at the end, or just call a small bet at the river. But at least you can put your strong opponent into a hand or into a few hands.
But with five or six weak players again, you'll have to be careful. They may have the hands above, but because they're weak, there will be more add-ons, like 8-5, J-5, Q-8, or even Q-5, all of which will add to the possibility of your K-Q being beaten.
Call a small bet at the river (because with many callers you are getting good pot odds to make the call). But when one moves all-in, it's a signal. Fold your K-Q. What hand could they be doing the all-in with? If the player's strong, you may have a clue. But with a weak player, you don't.
Why go to war if you don't know what you are trying to beat?
A strong player is willing to play more stronger hands than weaker ones. He is willing to play A-K more often than A-8 in his life, although frequency of play is no clue to how he plays specific hands. He remains unpredictable. But you will expect him to fold A-8 more often than A-K.
But weak players don't know what hands they are playing. They will play J-5 as readily as A-K. So, when playing with them, because you can't put them into a hand because they don't even know theirs, just show them a good enough hand. A Two-Pair or higher, more desirably. In the A-10 example above, you'll be happy with 3-3. In the second, I wish you have the 7-4 or the 10-9 before you act rashly.
And, unless you are just messing about in a free poker game don't attempt any fancy manoeuvres like all-in bluffs.
In the 5-6-J-Q-8 Board, don't move all-in with A-K. Even with just two weak opponents, they will just readily call you with K-Q as much as with 6-4, J-9, or even 3-3. They don't know the difference between them.
If they have something, they will be willing to take it along to death. So make your something stronger than their something, and take it to their death instead. No bluffs. No calling of suspected bluffs.
Remember - KISS - Keep it Simple or Straightforward; or KISS - Keep it Simple against Stupid Players!