The best spells to use are the ones that you create. After all, you are the one who truly understands your circumstances and what is needed to make changes. The most important thing I can tell you about creating your own spells is that you will get exactly what you put into it. If you just slap something together without any planning and research, the results will be just as sloppy. In order for a spell to be effective you have to have all elements of the spell vibrating in the same direction. If you plan to use herbs in your spell work, make sure the herbs you select have the appropriate planetary rulers. I have created a list for you of the more common Herbal Planetary Rulers . As you can see on that list, the elemental ruler is also included. This is to help you in choosing which herb would be best for adding more of a punch to a particular element needed for spells. Here is a list of Magickal Goals and the herbs used for that purpose.
In a perfect world you would also be able to pick the appropriate time (as in Planetary Hour and Moon sign and phase). To that end, here is a link to some excellent software that gives you the planetary hours and just about everything else you would need to plan your spell work: Chronos XP. Here also is a link to Lunabar, an excellent program that will display the current Moon phase and sign on your task bar, it even warns you when the moon is void-of-course. As always, your needs will outweigh all other factors, but try to get things as close as possible to their ideals.
Another important thing to consider is keeping track of everything you do magickally. That would include the sign the Moon is in, the herbs used, the candles, anything that you put into the spell, including your own frame of mind and your emotions.
The old saying "Be careful what you witch for" is really true. If you are wishing for someone new in your life, be as specific as you possibly can be. Make this person as real in your mind as you can. Don't forget about the qualities you want that person to have. Physical attributes are easy enough, but describe the kind of person you want as well. I had a friend who was ready for someone in her life and she asked for someone who would never leave her. He turned out to be, not only a possessive jerk, but a stalker as well.
As far as money spells go, if you need a specific amount such as your electric bill, work for that, but if your need is an overall increase in your money flow remember, that to achieve those things in your life will have to change. Perhaps a new job, more overtime, etc. You must be willing to accept the way it will be answered so long as you do no harm.