Patience is the hurdle most beginners struggle with. The biggest mistake is usually playing too many hands. If they have not seen a hand for 20 minutes, all of a sudden A4 looks like a monster in any position. Don’t do it. Patience is everything.
Secondly, watch! Watch how many hands someone plays and how they play them. Make mental notes. Watch. Ask how you can take advantage of what they are doing. Watch. Ask yourself are they doing something worth copying. Watch and keep thinking about it. Most experienced players do n’t! That’s why you can catch up and pass them. Put the effort into the thought process and you will be rewarded.
Respect a re-raise. If you have raised with AJ, and someone has re-raised, then they probably have you well beat. Learn to swallow. Pass. (The exception to this, is in major championships. Good players will re-raise with anything at a major event. You need to know which will though, and which won’t.)
When you reach a reasonable standard and start playing with better players, mix it up. When the whole table knows you are passing A4 in early position and raising AQ in late position. Try mixing it up. Raise with suited connectors occasionally. This can have several benefits. You can often steal when the flop comes high. Secondly, you often get called when you hit the flop.
Now we are majoring in contradictions, let’s contradict the patience argument. Be aware of your chip stack compared to the Blinds. Don’t let yourself get too low. A lot of good cash players can’t win tournaments because they blind themselves to death. If you have less than 3 times the big blind, you are in trouble. Make a move before this happens. Even with A4 when needs must.