Keep in mind the most powerful items demand respect or they'll fuck with you. They're conscious, albeit non-human consciousness.
Stones (meaning crystals) are good consciousness carriers but you've got to spend time working with them to get what you want out of them, and be wary of whatever handling they may have gotten on the way (i.e. chinese-sourced stones that may have used slave labor), they'll retain anything they picked up on their way to you and you'll have to deal with that too.
Solomon's seals are some of the most powerful, and you can make your own if you know what you're doing. Respect is paramount, though, you're calling upon archangels and demons there, so if you're going to use them, use them appropriately. A bit of life energy goes a long way there, especially if you're buying something someone else made (a bit of blood or whatever, don't be a pussy). Ideally you make it yourself, the best life energy is labor (that's the other type of blood sacrifice). Something you made or mined yourself will always be stronger than something bought, it's time-as-proxy (money) vs time-direct (labor).
This is why what >>123575 said is so accurate. Putting your own energy into it makes you feel it as real. Even if the self-made item is "worse", a handmade altar table will feel much more powerful than one bought off the rack, and if it's your own handiwork, it's that much more personal. If it becomes a generational item, it becomes that much stronger: Your essence, passed down to your children and grandchildren, they'll feel your strength through the handed down item (it becomes a "trigger object" so to speak, or a psychic anchor). It doesn't have to be fancy, just something you were putting your full attention into making (i.e. don't work while watching TV, music is cool if it's personal to you of course).
Specific to your malas, this should have everything you need to know: https://isha.sadhguru.org/us/en/wisdom/article/the-significance-of-rudraksh