I often try to not even pick up my club when waiting for a slow group in front of me until I'm ready to hit the shot. This helps me stay relaxed and not overthink the shot.

This is also what I was going to suggest. Go ahead and get your yardage, but don't pull a club and stand there with it in your hand while you wait. And definitely don't address the ball until you are clear. I've known guys after long wait to grab a club and address the ball while the group in front is still walking off the green and then stand there until they can hit. Wait until you are completely clear to start your pre-shot routine.

Picture yourself behind a foursome, Cart Path only due to last night's rain. The first player in the group walks over to their ball, lasers pin, then walks back to get club, after three practice swings, the player fails to make decent contact and tops the ball 30yards--new distance and club needed. Hope I triggered some of you!

I definitely feel like slow play after a good few holes changes your rhythm.

Next time, start a conversation with your imaginary caddie about the imaginary crowd awaiting your next shot. Or practice your stinger wedge. Or hit into the group. All better options than getting frustrated.

I’ve had the same problem. Recently I was playing and there was a downhill green that was drivable but there was a group in front of mine so I had to wait 5+ min till I could attempt it and it got in my head so much that I went completely under the ball and went in the trees. Pace of play is so important when you get up to higher levels of playing

Golf courses out here in socal are letting too many walk ons show up to the point that I had a round where I waited thirty minutes to tee off at each hole. It was terrible. All we could do was listen to music and try to kill time while swinging our clubs to stay loose.

Rare I can get a tee time as a single unless playin 9 after 3-5 pm on weekends. Well, some days during the week, but I don’t want to encourage y’all to retire and compete with me for times.
The pros , especially the top quarter of the leaderboard on weekends will typically take 5+ hours. If they can overcome the 6 inch handicap (between the ears) then I should be able to stay focused and not watch the clock. If I have a time limit of 4 hours, I can just walk off having enjoyed being on course, even if it was 2:30 for 9 holes.
That rates are escalating while the number of rounds are skyrocketing annoys me to no end. But I put that in my back pocket, physically and mentally, once out of the pro shop. It is what it is.

Played today and was reminded that golf etiquette is dead. The GM of the golf course we were playing was in the group in front of us. Never let us play thru. They literally held us up for 18 holes. They were hitting it all over the place. Losing golf balls. Not playing ready golf. The group in front of them gapped them by almost 2 holes just on the front 9. Ridiculous....

Whenever I run into these situations, I just know I need to stay focused. It can be easy to start messing around with friends and talking, but if you are really worrying about your score, you have to prioritize that. Take practice swings, envision future shots on your hole, and develop a gameplay for future holes. These tend to help me and hope they can help you too!

As others jave stated it can be very difficult to get back "in the zone" once that zone bubble has been busted. Frustration is never good as it just tenses the body. I just try not to watch the hordes in front of me and play my shot when it is safe for me to do so.

I do admit to being frustrated after following a group for 18 holes when they exit the green on the 18th go their carts and start emptying their pockets, chatting, adding up their score, etc...DO THAT IN THE PARKING LOT!!!

Try slowing some things down during your round and most importantly pay attention only on your own game. Its common to see someone make the mistake of thinking about the group behind or watching the group ahead. Its difficult to concentrate on your own game when your thoughts are on the group in front of you. Letting the group ahead of you play on a little longer to make space before you tee off should help your round become more fluid and help free up traffic. To help keep your mindset stable during a slow round, try to find an interest in a science or nature that golf courses provide to keep your thoughts busy until its time to dial in on your upcoming shot.

Best advice is be patient and enjoy the day. You can only control your own game.
I can't count the times where we have complained on the tee about the group ahead of us hitting their third shot to get out of range, and then one of us skulls it 30 yards. Do something fun while waiting. When your mood goes down, so goes your game.
True the new "party attitude" of golf has created a monster of unnecessary long rounds, but several things can lead to what we consider slow play.
Many times it starts with the tee times spaced at 9 minute intervals, with a notice on the cart to play 4 hours and 15 minute rounds. Do the math. That only works if you can get a group through the round in under 3 hours. Playing by yourself - yes. A group of 4 - not likely. At some point it's going to start backing up.
Be patient an enjoy the day. You can only control your own game.
Many times I have been placed behind a group of seniors who don't hit it that far anymore. I'm approaching that age where I will be one of them soon, so give them a little slack.
Be patient an enjoy the day. You can only control your own game.
Other times I have been placed behind a group with youngsters or a spouse learning the game. Use that down time to encourage them. Nothing can drive a youngster or spouse away from the game better than a bunch of jerks trying to get done quick so they can get to the bar by kickoff.
Be patient an enjoy the day. You can only control your own game.

Maybe put yourself in the mindset that you are starting over again you opened up 1 under through 4, just talk yourself mentally into a fresh new set if holes and try your best to go 1 under through 4 again or 1 under through 1 mindset

Work on your swing while you are idly awaiting you turn. I have a Orange whip in my bag which is easy to grab, keeps the muscles loose and maintain some tempo. Like playing baseball and you are on desk warming up. Hakuna matata.