If you've read the last Harry Potter books or watched the sixth movie in the series, you may remember coming across with the term 'horcrux'. To those who have had better things to do with their lives, let me inform you quickly: horcruxes are objects in which Voldemort hid parts of his soul to become immortal.
But here's the trick: Voldemort isn't by far the only one who can do this. In fact, anyone, even muggles, can do it - and when a muggle does it, no murder is required, and mortality is secured!
So why make a horcrux? Well, suppose something you've done or not done or said or left unsaid in the past is weighing on your mind constantly, preventing you from living your life to the fullest. It would be something you regret, something you had control over that didn't end well, or some compulsive mental model or way of thinking or acting that's giving you constant regret. I could also be something that was done to you, something you had no control over, that you just cannot leave in the past.
This load on your mind can be lifted off and transferred into an object that will carry that part on your behalf.
The process of creating a muggle horcrux differs a little from that of the magical horcrux. It'll also take a little more time. Here are the steps:
Find a small object that fits nicely in your hand. It should be something you don't need for other purposes and something you can carry with you if needed. (For example, I used a medallion.)
Write out a mantra specifically for the creation process. It doesn't have to say anything about the memory or thought you're transferring into the horcrux - it could be just random words - but I recommend using phrases that make you feel powerful and self-respected. (For example, when I created a horcrux I used a medium-length poem as the mantra, climaxing in the words " But I refuse to surrender".)
When you notice the negative feeling is present, be it regret or grudge or compulsive thinking, take the horcrux in your hand and squeeze it as hard as you can while saying the mantra either out loud or silently in your mind. Repeat this every time you notice there's still a part or the negativity in you. You may have to do this every day (or even multiple times a day) in the beginning but the need will diminish in time with every ritual you perform. (It took me about six months, maybe a couple more, to complete the transfer and create a full horcrux. But it might take even longer.)
If you have more than one great regret or compulsive thought pattern that clearly concern separate things, I suggest using different objects and different mantras for each of them. There is no limit to how many horcruxes you can create. Just remember to let go of it once it's full.
The effect of this technique is so profound it's almost like real magic.
P.S. I'm not actually sure if you'll stay mortal after creating a horcrux like this. I guess I'll find out later.