I use Ticklers as well, but on the Palm instead of hard files.
I also have a basket on my desk that is reserved for only bills due, and checks that need to be deposited. I put the bills into the basket when they come in, and my Tickler system is set up to pop up the bill and approx amount when it's time to pay.
I update the books every week, and depending on the cashflow situation I'll sometimes go ahead and take care of all pending bills at the next update, or I'll take care of them as they're due. If I take care of them all at once, I then drop into my @Ticklers list on the Palm, and mark the upcoming ones as completed.