Focus on every detail and information at the table, online or live, there are many edges you can gain.
Examine chip stack sizes (certain sized stacks act a certain way), for example, a medium stacked individual likes their position and will usually only engage with a quality hand (be careful), while a big stack will open their range and try to steal and pressure shorties.
There are more indicators at the table (bet sizing - and how a player might adjust it moving later into the event, or how active a player starts to get when they are lower in chips and aggression is their only tool until their stack is inconsequential.
Good luck, stay alive, watch everything, especially when waiting or not in a hand.