I was introduced into chanting mantras by a good friend of mine about 4 months ago. As a follower of the "Law of Attraction" beliefs, we both had a similar take on it - the Law of Attraction ways sometimes worked for us, sometimes it did not. But my friend pointed out to me that he was introduced into mantras and how chanting them "actually works!" for him. So I gave it a test for 40 days.
Here are 2 mantras my friend gave me:
For abundance, say "Om Shrim Shrim Shrim Maha Lakshmiyei Namaha" (however, I later researched that instead of "Namaha", if you're over 28, say "Swaha")
For just overall positive, "good luck", things coming your way, say "Om Sharavana Bhavaya Namaha" (oddly, I haven't heard people replace "Namaha" with "Swaha" when saying this mantra. Some say there are some mantras that require it, and some that do not. I guess this is one of those exceptions.)
State your intention and then just chant your mantra. Say it for 54-108 times a day, twice a day. I've noticed that "54" is the same number of beads found on the main part of the rosary. Also, if you're at work or any other public place, I've heard you can just say it silently, in your head. You can even just chant the mantra throughout your day, silently or aloud.
Say the mantra for at least 40 days. But some say to go even further than 40 days. My friend has told me how a lot of people stop halfway because they're not noticing anything. So keep on going!
Just notice that "abundance" may not necessarily show up as abundance in finances. It could show up as an abundance of friends, an abundance in love, etc.
After chanting the "abundance" mantra for about a month and a half, I did notice that I was able to discover unnecessary expenses. My husband's schedule changed and we were able to adjust our children's care expenses. And my husband got a couple of raises. All these changes ultimately are now saving us around $500-600/month. I also got "more" responsibilities at work that could easily affect my future bonuses/raises in a positive manner.