Writing your own spell will work better than the ones on this site, because it has more meaning to you. Putting your energy and intent into the spell is the most important piece, however. You could always pick and choose bits from spells, like chants or items, that you want to use in your own. That's what I do. Also, look up correspondences and, if you want, crystals or such.
Writing spells seems scary and hard at the start, I know. Some money spells on this site I like are:
Obviously, you don't need to do everything in these spells. You can modify them to fit your needs and what you feel most comfortable with. Good luck!