As a beginner, I’ve enjoyed learning and utilizing jar magic. I feel like it’s a mini therapy session, I can put a lot of energy and emotion into them, and then release!
I created a sour jar for a group of people today, something new for me. There is no way not to sound petty, but I want them the have bad luck on vacation. They have been causing hurt lately and it is just not sitting right that they go off and enjoy each other. Also, I’m human and can be, well, petty.
I’m did a three card spread reading first, concentrating on whether it would be worth my time to proceed with jar and felt a good sense to go ahead. I based jar off a video I’d seen for a break-up jar. Names of individuals, used coffee grounds, salt, red and black pepper and vinegar. Black pepper wouldn’t be an ad-in I would usually go to, but last night I had a dream that I was working in a restaurant and ruined a dish by adding too many black peppercorns, so I figured why not? Hope it ruins their vacation 
I would love anyone’s thoughts on keeping the jar around, I usually dispose of a sour jars as soon as I’m done. But I am thinking of keeping this one for the duration of their vacation and giving it a good shake every day.
Again, beginner here so thoughts and advice always welcome!
If you believe that it is working or is working then it is. Dont think about them at all, forget them. If you do then the spell will do its thing for you. I suggest putting the jar in a safe place or possibly burying it upside down. If the jar reminds you of the people then I suggest putting it somewhere where you wont see it. As long as you don’t think about them & believe it works then it will go as planned
I’ve done similar to both a small group of people and it curse jars for individuals. I usually keep the jars then dispose of them when I no longer feel sour myself about them, sometimes until I forget what it was for. I know for some people, as NightCrawler demonstrates, forgetting and not thinking about it helps the magic be released, which is especially popular for chaos magic. Either way works, it depends on what works best for you.
Be confident it will work and give it an extra shake for a good boost. Good luck! 