Penny was always a great support to her friends. And throughout the course of TBBT she dished quite a few pieces of good advice.
TBBT: Taking Sheldon Suit Shopping
In season 3 episode 18, ‘The Pants Alternative’ Sheldon wins an award. And must give a speech in front of an audience. Which he knows he will struggle with. Somehow, even though he won’t stop talking around his friends. The idea of doing the exact same in front of strangers terrifies him
TBBT: ”Do As I Say, Not As I Do”
In season 11 episode 9, ‘The Bitcoin Entanglement’ in a flashback. Penny and Bernadette are still working at The Cheesecake Factory when Bernadette tells Penny about her break-up. Penny then states that the best way to get over a break-up is to take time to yourself.
TBBT: ”You Always Will Be Physicists”
In season 11 episode 2, ‘The Retraction Reaction’ Leonard and Sheldon feel like they have hit a dead end with physics. And are incredibly down as they feel like their careers and lives have amounted to nothing.
”Keep Your Mouth Off Other Women”
In season 8 episode 24, ‘The Commitment Determination’, Penny and Leonard decide to get married in Vegas. Sheldon points out that they have been engaged for a while but still haven’t set a date for their wedding. While in the car Leonard confesses to kissing another girl in the past. And Penny takes this as Leonard trying to sabotage the wedding. When in fact he just didn’t want any secrets between them.
Compromise Is Key
Season 10 ep 4, The Cohabitation Experimentation’, Amy and Sheldon are talking to Leonard and Penny, respectively, about moving in with one another. Penny offers Sheldon a lot of great advice but the most important one for Sheldon is “Compromise is key.”