Paying off debt and credit score is going down...

[FN]

Over the past year or so I've been able to pay off a lot of debt.  I've gone from a dozen loan accounts with balances to just two.  Some things (like student loans and 2nd mortgage) the accounts close when you pay them off and I notice that the FICO score goes down (**bleep**?).  Other accounts like credit cards I can keep open but just don't use.  But I noticed for example just today paid off one credit card (which is still open with a $30K limit) and the FICO score dropped 25 points.  

I don't really care because I have no plans for any additional debt in the foreseeable future, but I'm curious if there is some trick to avoid this...

[NRB525]

How much of your debt was in term loans, student loans, and "non Credit Card" debts?

When you paid off the latest $30k card, was any other credit card reporting a balance?

As of today, which debts are still reporting any balance (on the last statement) and what is the credit line associated with those items?

Which CC are now reporting zeros and what is the credit limit for each of those ?

If all credit cards are reporting $0 balances, then that is a situation that FICO doesn't seem to like. Many report seeing a score drop when all their revolving credit reports as zero balance. If one card reports something, then those situations usually see a score improvement.

Are you getting any new credit, any new card applications in the last year?

Lastly, where are you getting your FICO scores, and what are those scores now?