This may sound like a bit of an obvious tip for today but you would be surprised the number of people that play poker far above their level of expertise and encounter a monstrous losing streak because of it.
If there is a better poker player at the table than you then do not get involved as much. You stand a much better chance of making money by picking chips off of the weaker players.
There is nothing wrong with getting involved with better poker players, just don’t expect to win as much. Keep your wits about you and use your judgment to make the right calls.