It is really important to closely study each of your opponents when both playing and not playing
Novice players will often make the mistake of calling to see the flop even with hands that they should have folded. Also they will play hands that are obviously losing hands and
time and time again they will play to lose.
You will find only a very few novice players playing Hold'em in a conservative way, and they will call instead of folding time and time again. The reason they do is that they want to play
and they don't see any fun in folding and waiting.
You can spot these players as better players often raise more pre flop. So if you are playing at a table and their is a lot of raising you are likely to be up against a good player, so maybe you
should be thinking of getting out quickly.
Always at the start of a game (with new players you haven't played against before) assume that your opponents are better than you until you study and observe them and are confident they aren't.