It depends on why you need this money. If you need a specific amount to pay a bill asap, you want a raise, or just to find a few extra dollars here and there. Different spells work better in different situations.
Whenever I cast a money spell I go with a honey jar or charm to attract money. I usually get more tips at work, or the bank sometimes offers me something [lower interest rate, new savings account, increase credit limit. Though the last ones pointless for me, it does teach you should be specific]