Malkom2 said:
There is the book on
Bija Mantras by David Frawley that has a bunch of safe-to-use mantras in it. Just make sure to replace "Om" with "Aum" if you see it in a mantra anywhere. Also, "Namah" in his book is "Nama". No need for that extra "h" at the end.
Then there are also the
Necronomicon Mantras. They are not sanskrit but still an alternative collection of mantras that work, so I figured I should mention them as well. Ignore all the commentary by the author as he is deluded. The only stuff you need are the two names that build each mantra, and the sigil that is used together with them. You vibrate the first name for x number of times, and then the second name for x number of times, then state your affirmation, all while focusing on the respective sigil. It works like any normal working would, and requires atleast 40 days for permanence.
Also,
do not ever use the 20th, 21st, 22nd, and 23rd names. These are black magick names and if you vibrate them into yourself you will get very undesirable effects. Just do not use them, ever.
With any and all mantras, runes, and whatnot, always keep in mind that if it makes you feel bad in any way, that you should
stop using it. If you are unsure about a mantra, just vibrate it once with proper focus for like 5 minutes, and feel the energies. This should give you a good idea of what kind of energies you are raising with it, and if they feel weird or bad to you in any way, do not use that mantra.