OK - I don't play high stakes stuff but for live tournaments like our Pub Poker League final I spent a lot of time watching videos to see how good players dealt with the requirements of time (patience) position (not playing in the wrong position) and chips (do not waste chasing under 30% chances).
Sure odd bets do come off sometimes but most tournament play is tight with loose players able to be identified and noted. Also in live tournaments there are usually a few drinkers and those with obvious tells
- in other words it requires focus at all times even early in tournament.
Watch especially for the player who shows their cards when they pulls off a bluff - they will catch people by playing good hands the same way soon after so this style can be noted.
Online I just shut the door, turn off the phone, ignore my wife (the hardest part), and concentrate remembering early that the tournament will take 4 hrs so not waste chips early when not with the winning hand.
Oh - I'm partially deaf so my wife does not expect me to respond unless it is something really important.