Budget software is really helpful.
By the way your question is worded it seems like you're tight on money... but if its possible, iwth your smaller bills... see if you can get into the habit of paying a month in advance. this way, if you "miss" a payment...you will still have time to pay.
Example: I pay my credit card bills when the bill POSTS... not when its due. (Posted Aug 6th... due September 8th) This way if i mismanaged my money or whatever, i have 3-4 weeks in which i can still pay it off and not be late.